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Bouhy J, Roy N, Dekoninck A, Poot J, Yans J, Deparis O. Unsupervised topological analysis of polarized light microscopy: application to quantitative birefringence imaging. Appl Opt 2024; 63:1188-1195. [PMID: 38437296 DOI: 10.1364/ao.507553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 01/11/2024] [Indexed: 03/06/2024]
Abstract
The determination of birefringence (magnitude and axis orientation) of optical materials is of significant interest in various fields. In the case of composite samples, this task becomes complicated and time-consuming; therefore, a partially automated procedure for reconstructing birefringence spatial distribution becomes valuable. Herein, we propose a procedure to reconstruct the spatial distributions of the retardance and optical axis orientation in a geological thin section from sparse quantitative birefringence measurements, using automatic boundary detection on cross-polarized light microscopy images. We examine two particular areas on the selected geological thin section: one that presents a uniaxial crystal with a circular cross-section of its refractive index ellipsoid and the other with grains of varying orientations. The measurement gives the orientation of the grain's optical axis both in and out of the plane of the thin section, which explains the qualitative observations with the cross-polarized light microscope. Future work will connect the measured orientation of the rock thin section with its 3D geological orientation in the field.
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Gravis D, Roy N, Ruffini-Ronzani N, Houssiau L, Felten A, Tumanov N, Deparis O. Secondary ion mass spectrometry, a powerful tool for revealing ink formulations and animal skins in medieval manuscripts. R Soc Open Sci 2023; 10:230059. [PMID: 37293355 PMCID: PMC10245198 DOI: 10.1098/rsos.230059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 04/06/2023] [Indexed: 06/10/2023]
Abstract
Book production by medieval scriptoria have gained growing interest in recent studies. In this context, identifying ink compositions and parchment animal species from illuminated manuscripts is of great importance. Here, we introduce time-of-flight secondary ion mass spectrometry (ToF-SIMS) as a non-invasive tool to identify both inks and animal skins in manuscripts, at the same time. For this purpose, both positive and negative ion spectra in inked and non-inked areas were recorded. Chemical compositions of pigments (decoration) or black inks (text) were determined by searching for characteristic ion mass peaks. Animal skins were identified by data processing of raw ToF-SIMS spectra using principal component analysis (PCA). In illuminated manuscripts from the fifteenth to sixteenth century, malachite (green), azurite (blue), cinnabar (red) inorganic pigments, as well as iron-gall black ink, were identified. Carbon black and indigo (blue) organic pigments were also identified. Animal skins were identified in modern parchments of known animal species by a two-step PCA procedure. We believe the proposed method will find extensive application in material studies of medieval manuscripts, as it is non-invasive, highly sensitive and able to identify both inks and animal skins at the same time, even from traces of pigments and tiny scanned areas.
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Affiliation(s)
- David Gravis
- Namur Institute of Structured Matter (NISM), University of Namur, Namur 5000, Belgium
- Heritages, transmissions, inheritances institute (PaTHs), University of Namur, Namur 5000, Belgium
| | - Nicolas Roy
- Namur Institute of Structured Matter (NISM), University of Namur, Namur 5000, Belgium
- Namur Institute for Complex Systems (naXys), University of Namur, Namur 5000, Belgium
| | - Nicolas Ruffini-Ronzani
- Centre de recherche Pratiques médiévales de l’écrit (PraME), Department of History, University of Namur, Namur 5000, Belgium
| | - Laurent Houssiau
- Namur Institute of Structured Matter (NISM), University of Namur, Namur 5000, Belgium
| | - Alexandre Felten
- Namur Institute of Structured Matter (NISM), University of Namur, Namur 5000, Belgium
- Synthesis, irradiation & analysis of materials (SIAM) technological platform, University of Namur, Namur 5000, Belgium
| | - Nikolay Tumanov
- Namur Institute of Structured Matter (NISM), University of Namur, Namur 5000, Belgium
- Physico-chemical characterization (PC2) technological platform, University of Namur, Namur 5000, Belgium
| | - Olivier Deparis
- Namur Institute of Structured Matter (NISM), University of Namur, Namur 5000, Belgium
- Heritages, transmissions, inheritances institute (PaTHs), University of Namur, Namur 5000, Belgium
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Lourdu Madanu T, Chaabane L, Mouchet SR, Deparis O, Su BL. Manipulating multi-spectral slow photons in bilayer inverse opal TiO 2@BiVO 4 composites for highly enhanced visible light photocatalysis. J Colloid Interface Sci 2023; 647:233-245. [PMID: 37253292 DOI: 10.1016/j.jcis.2023.05.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 05/11/2023] [Accepted: 05/17/2023] [Indexed: 06/01/2023]
Abstract
Manipulation of light has been proved to be a promising strategy to increase light harvesting in solar-to-chemical energy conversion, especially in photocatalysis. Inverse opal (IO) photonic structures are highly promising for light manipulation as their periodic dielectric structures enable them to slow down light and localize it within the structure, thereby improving light harvesting and photocatalytic efficiency. However, slow photons are confined to narrow wavelength ranges and hence limit the amount of energy that can be captured through light manipulation. To address this challenge, we synthesized bilayer IO TiO2@BiVO4 structures that manifested two distinct stop band gap (SBG) peaks, arising from different pore sizes in each layer, with slow photons available at either edge of each SBG. In addition, we achieved precise control over the frequencies of these multi-spectral slow photons through pore size and incidence angle variations, that enabled us to tune their wavelengths to the electronic absorption of the photocatalyst for optimal light utilization in aqueous phase visible light photocatalysis. This first proof of concept involving multi-spectral slow photon utilization enabled us to achieve up to 8.5 times and 2.2 times higher photocatalytic efficiencies than the corresponding non-structured and monolayer IO photocatalysts respectively. Through this work, we have successfully and significantly improved light harvesting efficiency in slow photon-assisted photocatalysis, the principles of which can be extended to other light harvesting applications.
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Affiliation(s)
- Thomas Lourdu Madanu
- Laboratory of Inorganic Materials Chemistry (CMI), University of Namur, Rue de Bruxelles, 61, 5000 Namur, Belgium
| | - Laroussi Chaabane
- Laboratory of Inorganic Materials Chemistry (CMI), University of Namur, Rue de Bruxelles, 61, 5000 Namur, Belgium
| | - Sébastien R Mouchet
- Solid-State Physics Laboratory (LPS) & Namur Institute of Structured Matter (NISM), University of Namur, Rue de Bruxelles, 61, 5000 Namur, Belgium; School of Physics, University of Exeter, Physics Building, Stocker Road, Exeter EX4 4QL, UK
| | - Olivier Deparis
- Solid-State Physics Laboratory (LPS) & Namur Institute of Structured Matter (NISM), University of Namur, Rue de Bruxelles, 61, 5000 Namur, Belgium
| | - Bao-Lian Su
- Laboratory of Inorganic Materials Chemistry (CMI), University of Namur, Rue de Bruxelles, 61, 5000 Namur, Belgium; State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, Hubei, China.
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Madanu TL, Mouchet SR, Deparis O, Liu J, Li Y, Su BL. Tuning and transferring slow photons from TiO 2 photonic crystals to BiVO 4 nanoparticles for unprecedented visible light photocatalysis. J Colloid Interface Sci 2023; 634:290-299. [PMID: 36535165 DOI: 10.1016/j.jcis.2022.12.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/28/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022]
Abstract
Periodic structures with alternating refractive indices such as inverse opal photonic crystals are capable of reducing the group velocity of light such that this slowed light can be more efficiently harvested for highly enhanced solar energy conversion. However, the generation, the manipulation and, in particular, the practical applications of these slow photons remain highly challenging. Here, we report the first proof of concept on the ability to control, in an inverse opal TiO2-BiVO4 hetero-composite, the transfer of slow photons generated from the inverse opal photonic structure to the photocatalytically active BiVO4 nanoparticles for highly enhanced visible light photoconversion. Tuning the slow photon frequencies, in order to accommodate the electronic band gap of BiVO4 for slow photon transfer and for significantly improved light harvesting, was successfully achieved by varying the structural periodicity (pore size) of inverse opal and the light incidence angle. The photocatalytic activity of BiVO4 in all inverse opal structures, promoted by slow photon effect, reached up to 7 times higher than those in the non-structured compact films. This work opens new avenues for the practical utilization of slow photon effect under visible light in photocatalytic energy-related applications like water splitting and carbon dioxide reduction and in photovoltaics.
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Affiliation(s)
- Thomas L Madanu
- Laboratory of Inorganic Materials Chemistry (CMI), University of Namur, Rue de Bruxelles, 61-B-5000 Namur, Belgium
| | - Sébastien R Mouchet
- Solid-State Physics Laboratory & Namur Institute of Structured Matter (NISM), University of Namur, Rue de Bruxelles, 61-B-5000 Namur, Belgium; School of Physics, University of Exeter, Physics Building, Stocker Road, Exeter EX4 4QL, UK
| | - Olivier Deparis
- Solid-State Physics Laboratory & Namur Institute of Structured Matter (NISM), University of Namur, Rue de Bruxelles, 61-B-5000 Namur, Belgium
| | - Jing Liu
- State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, Hubei, China
| | - Yu Li
- State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, Hubei, China
| | - Bao-Lian Su
- State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, Hubei, China.
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Bouhy J, Dekoninck A, Voue M, Deparis O. Analysis of accuracy and ambiguities in spatial measurements of birefringence in uniaxial anisotropic media: publisher's note. Appl Opt 2022; 61:10062. [PMID: 36606839 DOI: 10.1364/ao.479363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Indexed: 06/17/2023]
Abstract
This publisher's note corrects an error in Appl. Opt.61, 8081 (2022)APOPAI0003-693510.1364/AO.463657.
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Bouhy J, Augustin D, Voué M, Deparis O. Analysis of accuracy and ambiguities in spatial measurements of birefringence in uniaxial anisotropic media. Appl Opt 2022; 61:8081-8090. [PMID: 36255939 DOI: 10.1364/ao.463657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 08/21/2022] [Indexed: 06/16/2023]
Abstract
Accuracy and ambiguities in retardance and optical axis orientation spatial measurements are analyzed in detail in the context of the birefringence imaging method introduced by Shribak and Oldenbourg [Appl. Opt.42, 3009 (2003)APOPAI0003-693510.1364/AO.42.003009]. An alternative formula was derived in order to determine the optical axis orientation more accurately, and without indetermination in the case of a quarter-wave plate sample. Following Shribak and Oldenbourg's experimental configuration using two variable retarders, a linear polarizer, and five polarization probes, we examined the effect of the swing angle χ, which selected the ellipticity of each polarization state, on the accuracy of retardance (Δ) and axis orientation (ϕ) measurements. Using a quarter-wave plate, excellent agreement between measured and expected values was obtained for both the retardance and the axis orientation, as demonstrated by the statistical analysis of Δ and ϕ spatial distributions. The intrinsic ambiguity in the determination of Δ and ϕ for superimposed layers of transparent anisotropic cello-tape is discussed in detail, and solutions are provided to remove this ambiguity. An example of application of the method on geological samples is also presented. We believe our analysis will guide researchers willing to exploit this long-standing method in their laboratories.
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Mayer A, Bi H, Griesse-Nascimento S, Hackens B, Loicq J, Mazur E, Deparis O, Lobet M. Genetic-algorithm-aided ultra-broadband perfect absorbers using plasmonic metamaterials. Opt Express 2022; 30:1167-1181. [PMID: 35209282 DOI: 10.1364/oe.442405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/11/2021] [Indexed: 06/14/2023]
Abstract
Complete absorption of electromagnetic waves is paramount in today's applications, ranging from photovoltaics to cross-talk prevention into sensitive devices. In this context, we use a genetic algorithm (GA) strategy to optimize absorption properties of periodic arrays of truncated square-based pyramids made of alternating stacks of metal/dielectric layers. We target ultra-broadband quasi-perfect absorption of normally incident electromagnetic radiations in the visible and near-infrared ranges (wavelength comprised between 420 and 1600 nm). We compare the results one can obtain by considering one, two or three stacks of either Ni, Ti, Al, Cr, Ag, Cu, Au or W for the metal, and poly(methyl methacrylate) (PMMA) for the dielectric. More than 1017 configurations of geometrical parameters are explored and reduced to a few optimal ones. This extensive study shows that Ni/PMMA, Ti/PMMA, Cr/PMMA and W/PMMA provide high-quality solutions with an integrated absorptance higher than 99% over the considered wavelength range, when considering realistic implementation of these ultra-broadband perfect electromagnetic absorbers. Robustness of optimal solutions with respect to geometrical parameters is investigated and local absorption maps are provided. Moreover, we confirm that these optimal solutions maintain quasi-perfect broadband absorption properties over a broad angular range when changing the inclination of the incident radiation. The study also reveals that noble metals (Au, Ag, Cu) do not provide the highest performance for the present application.
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Ruffini-Ronzani N, Nieus JF, Soncin S, Hickinbotham S, Dieu M, Bouhy J, Charles C, Ruzzier C, Falmagne T, Hermand X, Collins MJ, Deparis O. A biocodicological analysis of the medieval library and archive from Orval Abbey, Belgium. R Soc Open Sci 2021; 8:210210. [PMID: 34109043 PMCID: PMC8170200 DOI: 10.1098/rsos.210210] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 04/28/2021] [Indexed: 05/30/2023]
Abstract
Biocodicological analysis of parchments from manuscript books and archives offers unprecedented insight into the materiality of medieval literacy. Using ZooMS for animal species identification, we explored almost the entire library and all the preserved single leaf charters of a single medieval Cistercian monastery (Orval Abbey, Belgium). Systematic non-invasive sampling of parchment collagen was performed on every charter and on the first bifolium from every quire of the 118 codicological units composing the books (1490 samples in total). Within the genuine production of the Orval scriptorium (26 units), a balanced use of calfskin (47.1%) and sheepskin (48.5%) was observed, whereas calfskin was less frequent (24.3%) in externally produced units acquired by the monastery (92 units). Calfskin was preferably used for higher quality manuscripts while sheepskin tends to be the standard choice for 'ordinary' manuscript book production. This finding is consistent with thirteenth-century parchment accounts from Beaulieu Abbey (England) where calfskin supply was more limited and its price higher. Our study reveals that the making of archival documents does not follow the same pattern as the production of library books. Although the five earliest preserved charters are made of calfskin, from the 1230s onwards, all charters from Orval are written on sheepskin.
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Affiliation(s)
- Nicolas Ruffini-Ronzani
- Research Centre ‘Pratiques médiévales de l’écrit’, University of Namur, 61 rue de Bruxelles, Namur 5000, Belgium
| | - Jean-François Nieus
- Research Centre ‘Pratiques médiévales de l’écrit’, University of Namur, 61 rue de Bruxelles, Namur 5000, Belgium
| | - Silvia Soncin
- BioArCh, Department of Archaeology, University of York, York YO10 5DD, UK
| | - Simon Hickinbotham
- BioArCh, Department of Archaeology, University of York, York YO10 5DD, UK
| | - Marc Dieu
- Mass Spectrometry platform, University of Namur, 61 rue de Bruxelles, Namur 5000, Belgium
| | - Julie Bouhy
- Department of Physics, and Heritage, Transmissions and Inheritances Institute, University of Namur, 61 rue de Bruxelles, Namur 5000, Belgium
| | - Catherine Charles
- Rare Books Collection, Bibliothèque Universitaire Moretus Platin, University of Namur, 61 rue de Bruxelles, Namur 5000, Belgium
| | - Chiara Ruzzier
- Research Centre ‘Pratiques médiévales de l’écrit’, University of Namur, 61 rue de Bruxelles, Namur 5000, Belgium
| | - Thomas Falmagne
- Rare Books Collection, National Library of Luxembourg, Luxembourg 1855
| | - Xavier Hermand
- Research Centre ‘Pratiques médiévales de l’écrit’, University of Namur, 61 rue de Bruxelles, Namur 5000, Belgium
| | - Matthew J. Collins
- Department of Archaeology, University of Cambridge, Cambridge CB2 3ER, UK
- GLOBE Institute, University of Copenhagen, Copenhagen 1350, Denmark
| | - Olivier Deparis
- Department of Physics, and Heritage, Transmissions and Inheritances Institute, University of Namur, 61 rue de Bruxelles, Namur 5000, Belgium
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Abstract
Eggshells are essential for the reproduction of birds since the optical properties of shells may have an impact on biological functions such as heating and UV protection, recognition by parents or camouflage. Whereas ultraviolet reflection by some bird eggshells has been recently described, its physical origin remains poorly understood. In this study, we identified a porous structure in eggshells. Using Mie scattering modelling, we found it was most likely responsible for reflectance peaks (intensities of ca. 20-50%) observed in the near-UV range. These peaks were observed by spectrophotometric measurements from eggshells of several breeds of hen, one breed of duck and one breed of quail. This optical response was interpreted in terms of the distinct visual perception of hens and humans: eggshells appearing achromatic for humans proved to be chromatic for hens. Fluorescence emission from these eggs was also characterised and attributed to the presence of protoporphyrin IX and biliverdin IXα in the shells. Electron microscopy observations revealed the presence of pores within the so-called calcified shell part (i.e., at depths between ca. 20 μm and ca. 240 μm from the eggshell's outer surface). Mercury intrusion porosimetry allowed us to quantify the pore size distribution. Simulations of the UV response of this porous structure using Mie scattering theory as well as an effective approach accounting for multiple scattering indicate that these pores are responsible for the backscattering peaks observed in the UV range, in the case of beige hen eggshells. Due to the similarities between the pore size distributions observed for beige hen eggshells and other investigated poultry eggshells, we expect Mie backscattering to be the origin of the UV response of the eggshells of many other bird species.
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Affiliation(s)
- Mathieu Ladouce
- Department of Physics, Namur Institute of Structured Matter (NISM), University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium.
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Lobet M, Piron P, Dewalque J, Maho A, Deparis O, Henrist C, Loicq J. Efficiency enhancement of perovskite solar cells based on opal-like photonic crystals. Opt Express 2019; 27:32308-32322. [PMID: 31684446 DOI: 10.1364/oe.27.032308] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 09/28/2019] [Indexed: 06/10/2023]
Abstract
Perovskite solar cells have shown a tremendous interest for photovoltaics since the past decade. However, little is known on the influence of light management using photonic crystals inside such structures. We present here numerical simulations showing the effect of photonic crystal structuring on the integrated quantum efficiency of perovskite solar cells. The photo-active layer is made of an opal-like perovskite structure (monolayer, bilayer or trilayer of perovskite spheres) built in a T i O 2 matrix. Fano resonances are exploited in order to enhance the absorption, especially near the bandgap of perovskite material. The excitation of quasi-guided modes inside the absorbing spheres enhances the integrated quantum efficiency and the photonic enhancement factor. More specifically, a photonic enhancement factor as high as 6.4% is predicted in the case of spheres monolayer compared to an unstructured perovskite layer. The influences of sphere's radius and incident angle on the absorbing properties are also estimated. Those numerical results can be applied to the nascent field of photonic structuring inside perovskite solar cells.
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11
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Guyot C, Vandestrick P, Marenne I, Deparis O, Voué M. Growth dynamics and light scattering of gold nanoparticles in situ synthesized at high concentration in thin polymer films. Beilstein J Nanotechnol 2019; 10:1768-1777. [PMID: 31501748 PMCID: PMC6720325 DOI: 10.3762/bjnano.10.172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 08/03/2019] [Indexed: 06/10/2023]
Abstract
Background: Numerous optical applications of nano-objects require a dispersion of the nanoparticles in a dielectric matrix. In order to achieve high particle concentrations, one can, as an alternative, directly grow the particles in a polymer or an inorganic film by, e.g., thermal annealing. Results: Simple laser reflection experiments showed that this growth process induced light scattering at the film/air interface. We report on this phenomenon, considering the growth dynamics of gold nanoparticles in a polymer film. The scattering of light was studied by measuring the bi-directional reflection distribution function. In parallel with the observation of enhanced scattering, imaging ellipsometry in dynamics mode showed that local values of the ellipsometric angles Ψ and Δ were strongly modified by the annealing process. Conclusion: A diffraction pattern corresponding to local modifications of the optical properties of the film gradually appeared, which turned out to be the signature of the growth of the Au nanoparticles. Moreover, the monitoring of the statistical distribution of the ellipsometric angles during annealing helped evidencing two regimes in the dynamics of the nanoparticle growth and in the optical response of the nanocomposite.
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Affiliation(s)
- Corentin Guyot
- University of Mons, Physics of Materials and Optics, Research Institute for Materials Science and Engineering, Mons, Belgium
| | | | - Ingrid Marenne
- AGC Glass Europe - Technovation Centre, Gosselies, Belgium
| | | | - Michel Voué
- University of Mons, Physics of Materials and Optics, Research Institute for Materials Science and Engineering, Mons, Belgium
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12
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Decorte R, Polet C, Boudin M, Tilquin F, Matroule JY, Dieu M, Charles C, Carlier A, Lebecque F, Deparis O. An interdisciplinary study around the reliquary of the late cardinal Jacques de Vitry. PLoS One 2019; 14:e0201424. [PMID: 30794540 PMCID: PMC6386372 DOI: 10.1371/journal.pone.0201424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 01/18/2019] [Indexed: 11/24/2022] Open
Abstract
The reliquary of Jacques de Vitry, a prominent clergyman and theologian in the early 13th century, has experienced several transfers over the last centuries, which seriously question the attribution of the remains to the late Cardinal. Uncertainty about the year of his birth poses an additional question regarding his age at death in 1240. The reliquary, located in the Saint Marie d'Oigines church, Belgium, was reopened in 2015 for an interdisciplinary study around his relics as well as the Treasure of Oignies, a remarkable cultural heritage notably built from Jacques de Vitry's donation. Anthropological, isotopic and genetic analyses were performed independently on the remains found in the reliquary. Results of the analyses provided evidence that the likelihood that these remains are those of Jacques de Vitry is very high: the remains belong to the same human male individual and the historical tradition about his age is confirmed. In addition, a separate relic (left tibia) was analysed and found to match with the remains of the reliquary (right tibia). The unique Jacques de Vitry's mitre, made of parchment, was sampled non-destructively and the extracted parchment collagen was analysed by a proteomic method in order to determine the animal species. The results showed that, surprisingly, not all parts of the mitre were made from the same species. All together, these findings are expected to fertilize knowledge carried by historical tradition around the relics of Jacques de Vitry and his related cultural heritage.
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Affiliation(s)
- Ronny Decorte
- Forensic Biomedical Sciences, Department of Imaging & Pathology, KU Leuven (KUL), Leuven, Belgium
- Laboratory of Forensic Genetics and Molecular Archaeology, Department of Forensic Medicine, UZ Leuven (UZL), Leuven, Belgium
| | - Caroline Polet
- Department of Palaeontology, Royal Belgian Institute of Natural Sciences, Brussels, Belgium
| | - Mathieu Boudin
- Radiocarbon Dating Laboratory, Royal Institute for Cultural Heritage (KIK-IRPA), Brussels, Belgium
| | - Françoise Tilquin
- Research Unit in Microorganisms Biology (URBM), Narilis Institute, ILEE Institute, University of Namur, Namur, Belgium
| | - Jean-Yves Matroule
- Research Unit in Microorganisms Biology (URBM), Narilis Institute, ILEE Institute, University of Namur, Namur, Belgium
| | - Marc Dieu
- Mass Spectrometry Facility (MaSUN), University of Namur, Namur, Belgium
| | - Catherine Charles
- Moretus Plantin University Library, University of Namur, Namur, Belgium
| | | | | | - Olivier Deparis
- Heritages, Transmissions, Inheritances (PaTHs) Institute & Department of Physics, University of Namur, Namur, Belgium
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13
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Mouchet SR, Verstraete C, Mara D, Van Cleuvenbergen S, Finlayson ED, Van Deun R, Deparis O, Verbiest T, Maes B, Vukusic P, Kolaric B. Nonlinear optical spectroscopy and two-photon excited fluorescence spectroscopy reveal the excited states of fluorophores embedded in a beetle's elytra. Interface Focus 2019; 9:20180052. [PMID: 30603071 PMCID: PMC6304011 DOI: 10.1098/rsfs.2018.0052] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2018] [Indexed: 12/29/2022] Open
Abstract
Upon illumination by ultraviolet light, many animal species emit light through fluorescence processes arising from fluorophores embedded within their biological tissues. Fluorescence studies in living organisms are however relatively scarce and so far limited to the linear regime. Multiphoton excitation fluorescence analyses as well as nonlinear optical techniques offer unique possibilities to investigate the effects of the local environment on the excited states of fluorophores. Herein, these techniques are applied for the first time to study of the naturally controlled fluorescence in insects. The case of the male Hoplia coerulea beetle is investigated because the scales covering the beetle's elytra are known to possess an internal photonic structure with embedded fluorophores, which controls both the beetle's coloration and the fluorescence emission. An intense two-photon excitation fluorescence signal is observed, the intensity of which changes upon contact with water. A third-harmonic generation signal is also detected, the intensity of which depends on the light polarization state. The analysis of these nonlinear optical and fluorescent responses unveils the multi-excited states character of the fluorophore molecules embedded in the beetle's elytra. The role of form anisotropy in the photonic structure, which causes additional tailoring of the beetle's optical responses, is demonstrated by circularly polarized light and nonlinear optical measurements.
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Affiliation(s)
- Sébastien R. Mouchet
- School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
- Department of Physics and Namur Institute of Structured Matter (NISM), University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium
| | - Charlotte Verstraete
- Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200D, 3001 Heverlee, Belgium
| | - Dimitrije Mara
- L–Luminescent Lanthanide Lab, Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium
| | - Stijn Van Cleuvenbergen
- Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200D, 3001 Heverlee, Belgium
| | - Ewan D. Finlayson
- School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Rik Van Deun
- L–Luminescent Lanthanide Lab, Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium
| | - Olivier Deparis
- Department of Physics and Namur Institute of Structured Matter (NISM), University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium
| | - Thierry Verbiest
- Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200D, 3001 Heverlee, Belgium
| | - Bjorn Maes
- Micro- and Nanophotonic Materials Group, University of Mons, Place du Parc 20, 7000 Mons, Belgium
| | - Pete Vukusic
- School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Branko Kolaric
- Micro- and Nanophotonic Materials Group, University of Mons, Place du Parc 20, 7000 Mons, Belgium
- Center for Photonics, Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
- Old World Labs, 1357 N. Great Neck Road Suite 104, Virginia Beach, VA 23454, USA
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Liu J, Zhao H, Wu M, Van der Schueren B, Li Y, Deparis O, Ye J, Ozin GA, Hasan T, Su BL. Slow Photons for Photocatalysis and Photovoltaics. Adv Mater 2017; 29:1605349. [PMID: 28165167 DOI: 10.1002/adma.201605349] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/17/2016] [Indexed: 05/25/2023]
Abstract
Solar light is widely recognized as one of the most valuable renewable energy sources for the future. However, the development of solar-energy technologies is severely hindered by poor energy-conversion efficiencies due to low optical-absorption coefficients and low quantum-conversion yield of current-generation materials. Huge efforts have been devoted to investigating new strategies to improve the utilization of solar energy. Different chemical and physical strategies have been used to extend the spectral range or increase the conversion efficiency of materials, leading to very promising results. However, these methods have now begun to reach their limits. What is therefore the next big concept that could efficiently be used to enhance light harvesting? Despite its discovery many years ago, with the potential for becoming a powerful tool for enhanced light harvesting, the slow-photon effect, a manifestation of light-propagation control due to photonic structures, has largely been overlooked. This review presents theoretical as well as experimental progress on this effect, revealing that the photoreactivity of materials can be dramatically enhanced by exploiting slow photons. It is predicted that successful implementation of this strategy may open a very promising avenue for a broad spectrum of light-energy-conversion technologies.
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Affiliation(s)
- Jing Liu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, 430070, Wuhan, Hubei, China
| | - Heng Zhao
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, 430070, Wuhan, Hubei, China
| | - Min Wu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, 430070, Wuhan, Hubei, China
| | - Benoit Van der Schueren
- Laboratory of Inorganic Materials Chemistry (CMI), University of Namur, 61 rue de Bruxelles, B-5000, Namur, Belgium
| | - Yu Li
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, 430070, Wuhan, Hubei, China
| | - Olivier Deparis
- Solid State Physics Laboratory, University of Namur, 61 rue de Bruxelles, B-5000, Namur, Belgium
| | - Jinhua Ye
- Research Unit for Environmental Remediation Materials, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan
| | - Geoffrey A Ozin
- University of Toronto, Lash Miller Building Room 326 80 St. George Street, Toronto, Ontario, M5S3H6, Canada
| | - Tawfique Hasan
- Cambridge Graphene Centre, University of Cambridge, Cambridge, CB3 0FA, UK
| | - Bao-Lian Su
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, 430070, Wuhan, Hubei, China
- Clare Hall, University of Cambridge, Herschel Road, Cambridge, CB3 9AL, UK
- Laboratory of Inorganic Materials Chemistry (CMI), University of Namur, 61 rue de Bruxelles, B-5000, Namur, Belgium
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15
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16
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Mouchet SR, Lobet M, Kolaric B, Kaczmarek AM, Van Deun R, Vukusic P, Deparis O, Van Hooijdonk E. Controlled fluorescence in a beetle's photonic structure and its sensitivity to environmentally induced changes. Proc Biol Sci 2016; 283:rspb.2016.2334. [PMID: 28003460 DOI: 10.1098/rspb.2016.2334] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 11/17/2016] [Indexed: 11/12/2022] Open
Abstract
The scales covering the elytra of the male Hoplia coerulea beetle contain fluorophores embedded within a porous photonic structure. The photonic structure controls both insect colour (reflected light) and fluorescence emission. Herein, the effects of water-induced changes on the fluorescence emission from the beetle were investigated. The fluorescence emission peak wavelength was observed to blue-shift on water immersion of the elytra whereas its reflectance peak wavelength was observed to red-shift. Time-resolved fluorescence measurements, together with optical simulations, confirmed that the radiative emission is controlled by a naturally engineered photonic bandgap while the elytra are in the dry state, whereas non-radiative relaxation pathways dominate the emission response of wet elytra.
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Affiliation(s)
- Sébastien R Mouchet
- Department of Physics, University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium .,School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Michaël Lobet
- Department of Physics, University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium
| | - Branko Kolaric
- Department of Physics, University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium
| | - Anna M Kaczmarek
- L-Luminescent Lanthanide Lab, Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium
| | - Rik Van Deun
- L-Luminescent Lanthanide Lab, Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium
| | - Peter Vukusic
- School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Olivier Deparis
- Department of Physics, University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium
| | - Eloise Van Hooijdonk
- Department of Physics, University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium
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Pasteels JM, Deparis O, Mouchet SR, Windsor DM, Billen J. Structural and physical evidence for an endocuticular gold reflector in the tortoise beetle, Charidotella ambita. Arthropod Struct Dev 2016; 45:509-518. [PMID: 27725254 DOI: 10.1016/j.asd.2016.10.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 10/03/2016] [Accepted: 10/05/2016] [Indexed: 06/06/2023]
Abstract
Charidotella ambita offers a unique opportunity for unambiguously locating its gold reflector by comparing the structure of reflecting and non-reflecting cuticle of the elytron and pronotum. Using light microscopy and TEM, the reflector was located underneath the macrofiber endocuticle just above the epidermis. The reflector is a multilayer comprising up to 50 bilayers alternating high and low density layers parallel to the surface of the cuticle. It is chirped, i.e., showing a progressive decrease in layer thickness from approximately 150 nm-100 nm across its depth. The high density layers in contact with the endocuticle fuse to the last macrofiber when the reflector is interrupted by a trabecula, demonstrating their cuticular nature. Simulated reflectance spectra from models of the multilayer matched the reflection spectra measured on the major gold patch of the elytron of living specimens. Previous reports in adult insects exhibiting metallic colors located their reflector in the upper strata and structures of the cuticle, i.e., epicuticle, exocuticle, scales and hairs. Thus, the endocuticular location of the reflector in C. ambita (and other tortoise beetles) appears unique for adult insects. Gold reflection appears in C. ambita only when the synthesis of the macrolayer endocuticle is complete, which may take up to 2 weeks. The development of the gold reflector coincides with the start of mating behavior, possibly suggesting a signaling function in conspecific recognition once sexual maturity has been reached.
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Affiliation(s)
- Jacques M Pasteels
- Université Libre de Bruxelles, Evolutionary Biology and Ecology, C.P. 160/12, Avenue F.D. Roosevelt 50, B-1050 Brussels, Belgium.
| | - Olivier Deparis
- University of Namur (UNamur), Department of Physics, Physics of Matter and Radiation (PMR), Rue de Bruxelles 61, B-5000 Namur, Belgium.
| | - Sébastien R Mouchet
- University of Namur (UNamur), Department of Physics, Physics of Matter and Radiation (PMR), Rue de Bruxelles 61, B-5000 Namur, Belgium; University of Exeter, College of Engineering, Mathematics and Physical Sciences, Stocker Road, Exeter EX4 4QL, United Kingdom.
| | - Donald M Windsor
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama City, Panama.
| | - Johan Billen
- KU Leuven, Zoological Institute, Naamsestraat 59, Box 2466, B-3000 Leuven, Belgium.
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Abstract
Photonic structures encased by a permeable envelope give rise to iridescent blue color in the scales covering the male Hoplia coerulea beetle. This structure comprises a periodic porous multilayer. The color of these scales is known for changing from blue to green upon contact with water despite the presence of the envelope. This optical system has been referred to as a photonic cell due to the role of the envelope that mediates fluid exchanges with the surrounding environment. Following from previously studied liquid-induced changes in the color appearance of H. coerulea, we measured vapor-induced color changes in its appearance. This response to vapor exposure was marked by reflectance redshift and an increase in peak reflectance intensity. Different physico-chemical processes were investigated to explain the increase in reflectance intensity, a property not usually associated with vapor-induced optical signature changes. These simulations indicated the optical response arose from physisorption of a liquid film on the beetle scales followed by liquid penetration through the envelope and the filling of micropores within the body of the photonic structure.
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Poncelet O, Tallier G, Mouchet SR, Crahay A, Rasson J, Kotipalli R, Deparis O, Francis LA. Vapour sensitivity of an ALD hierarchical photonic structure inspired by Morpho. Bioinspir Biomim 2016; 11:036011. [PMID: 27159922 DOI: 10.1088/1748-3190/11/3/036011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The unique architecture of iridescent Morpho butterfly scales is known to exhibit different optical responses to various vapours. However, the mechanism behind this phenomenon is not fully quantitatively understood. This work reports on process developments in the micro-fabrication of a Morpho-inspired photonic structure in atomic layer deposited (ALD) materials in order to investigate the vapour optical sensitivity of such artificial nanostructures. By developing recipes for dry and wet etching of ALD oxides, we micro-fabricated two structures: one combining Al2O3 and TiO2, and the other combining Al2O3 and HfO2. For the first time, we report the optical response of such ALD Morpho-like structures measured under a controlled flow of either ethanol or isopropyl alcohol (IPA) vapour. In spite of the small magnitude of the effect, the results show a selective vapour response (depending on the materials used).
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Affiliation(s)
- Olivier Poncelet
- Institute of Information and Communication Technologies, Electronics and Applied Mathematics, Université catholique de Louvain, Place du Levant, 3, 1348 Louvain-la-Neuve, Belgium
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20
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Mouchet SR, Van Hooijdonk E, Welch VL, Louette P, Colomer JF, Su BL, Deparis O. Liquid-induced colour change in a beetle: the concept of a photonic cell. Sci Rep 2016; 6:19322. [PMID: 26758681 PMCID: PMC4725358 DOI: 10.1038/srep19322] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 12/11/2015] [Indexed: 11/09/2022] Open
Abstract
The structural colour of male Hoplia coerulea beetles is notable for changing from blue to green upon contact with water. In fact, reversible changes in both colour and fluorescence are induced in this beetle by various liquids, although the mechanism has never been fully explained. Changes enacted by water are much faster than those by ethanol, in spite of ethanol's more rapid spread across the elytral surface. Moreover, the beetle's photonic structure is enclosed by a thin scale envelope preventing direct contact with the liquid. Here, we note the presence of sodium, potassium and calcium salts in the scale material that mediate the penetration of liquid through putative micropores. The result leads to the novel concept of a "photonic cell": namely, a biocompatible photonic structure that is encased by a permeable envelope which mediates liquid-induced colour changes in that photonic structure. Engineered photonic cells dispersed in culture media could revolutionize the monitoring of cell-metabolism.
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Affiliation(s)
- Sébastien R. Mouchet
- Department of Physics, University of Namur (UNamur), Rue de Bruxelles 61, B-5000 Namur, Belgium
| | - Eloise Van Hooijdonk
- Department of Physics, University of Namur (UNamur), Rue de Bruxelles 61, B-5000 Namur, Belgium
| | - Victoria L. Welch
- Department of Physics, University of Namur (UNamur), Rue de Bruxelles 61, B-5000 Namur, Belgium
| | - Pierre Louette
- Department of Physics, University of Namur (UNamur), Rue de Bruxelles 61, B-5000 Namur, Belgium
| | - Jean-François Colomer
- Department of Physics, University of Namur (UNamur), Rue de Bruxelles 61, B-5000 Namur, Belgium
| | - Bao-Lian Su
- Laboratory of Inorganic Materials Chemistry (CMI), University of Namur (UNamur), Rue de Bruxelles 61, B-5000 Namur, Belgium
- Clare Hall College, University of Cambridge, Herschel Road, Cambridge CB3 9AL, United Kingdom
| | - Olivier Deparis
- Department of Physics, University of Namur (UNamur), Rue de Bruxelles 61, B-5000 Namur, Belgium
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Muller J, Herman A, Mayer A, Deparis O. A fair comparison between ultrathin crystalline-silicon solar cells with either periodic or correlated disorder inverted pyramid textures. Opt Express 2015; 23:A657-A670. [PMID: 26072890 DOI: 10.1364/oe.23.00a657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Fabrication of competitive solar cells based on nano-textured ultrathin silicon technology is challenging nowadays. Attention is paid to the optimization of this type of texture, with a lot of simulation and experimental results published in the last few years. While previous studies discussed mainly the local features of the surface texture, we highlight here the importance of their filling fraction. In this work, we focus on a fair comparison between a technologically realizable correlated disorder pattern of inverted nano-pyramids on an ultrathin crystalline-silicon layer, and its periodically patterned counterpart. A fair comparison is made possible by defining an equivalent periodic structure for each hole filling fraction. Moreover, in order to be as realistic as possible, we consider patterns that could be fabricated by standard patterning techniques: hole-mask colloidal lithography, nanoimprint lithography and wet chemical etching. Based on numerical simulations, we show that inverted nano-pyramid patterns with correlated disorder provide typically greater efficiency than their periodic counterparts. However, the hole filling fraction of the etched pattern plays a crucial role and may limit the benefits of the correlated disorder due to experimental restrictions on pattern fabrication.
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Abstract
Nanostructures are commonly used for developing superhydrophobic surfaces. However, available wetting theoretical models ignore the effect of vacuum photon-mode alteration on van der Waals forces and thus on hydrophobicity. Using first-principles calculations, we show that superhydrophibicity of nanostructured surfaces is dramatically enhanced by vacuum photon-mode tuning. As a case study, wetting contact angles of a water droplet above a polyethylene nanostructured surface are obtained from the interaction potential energy calculated as a function of the droplet-surface separation distance. This new approach could pave the way for the design of novel superhydrophobic coatings.
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Affiliation(s)
- Louis Dellieu
- Research Center in Physics of Matter and Radiation (PMR), Department of Physics, University of Namur, 61 rue de Bruxelles, B-5000 Namur, Belgium
| | - Olivier Deparis
- Research Center in Physics of Matter and Radiation (PMR), Department of Physics, University of Namur, 61 rue de Bruxelles, B-5000 Namur, Belgium
| | - Jérôme Muller
- Research Center in Physics of Matter and Radiation (PMR), Department of Physics, University of Namur, 61 rue de Bruxelles, B-5000 Namur, Belgium
| | - Michaël Sarrazin
- Research Center in Physics of Matter and Radiation (PMR), Department of Physics, University of Namur, 61 rue de Bruxelles, B-5000 Namur, Belgium
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Deparis O, Mouchet SR, Su BL. Light harvesting in photonic crystals revisited: why do slow photons at the blue edge enhance absorption? Phys Chem Chem Phys 2015; 17:30525-32. [DOI: 10.1039/c5cp04983k] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Enhanced absorption in TiO2 inverse opals with blue-edge slow photons is explained by loose field confinement in thin TiO2 skeleton.
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Affiliation(s)
- O. Deparis
- Solid-State Physics Laboratory
- University of Namur
- B-5000 Namur
- Belgium
| | - S. R. Mouchet
- Solid-State Physics Laboratory
- University of Namur
- B-5000 Namur
- Belgium
| | - B.-L. Su
- Laboratory of Inorganic Materials Chemistry (CMI)
- University of Namur
- B-5000 Namur
- Belgium
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Mayer A, Gaouyat L, Nicolay D, Carletti T, Deparis O. Multi-objective genetic algorithm for the optimization of a flat-plate solar thermal collector. Opt Express 2014; 22 Suppl 6:A1641-A1649. [PMID: 25607321 DOI: 10.1364/oe.22.0a1641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present a multi-objective genetic algorithm we developed for the optimization of a flat-plate solar thermal collector. This collector consists of a waffle-shaped Al substrate with NiCrOx cermet and SnO(2) anti-reflection conformal coatings. Optimal geometrical parameters are determined in order to (i) maximize the solar absorptance α and (ii) minimize the thermal emittance ε. The multi-objective genetic algorithm eventually provides a whole set of Pareto-optimal solutions for the optimization of α and ε, which turn out to be competitive with record values found in the literature. In particular, a solution that enables α = 97.8% and ε = 4.8% was found.
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Lobet M, Lard M, Sarrazin M, Deparis O, Henrard L. Plasmon hybridization in pyramidal metamaterials: a route towards ultra-broadband absorption. Opt Express 2014; 22:12678-12690. [PMID: 24921385 DOI: 10.1364/oe.22.012678] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Pyramidal metamaterials are currently developed for ultra-broadband absorbers. They consist of periodic arrays of alternating metal/dielectric layers forming truncated square-based pyramids. The metallic layers of increasing lengths play the role of vertically and, to a less extent, laterally coupled plasmonic resonators. Based on detailed numerical simulations, we demonstrate that plasmon hybridization between such resonators helps in achieving ultra-broadband absorption. The dipolar modes of individual resonators are shown to be prominent in the electromagnetic coupling mechanism. Lateral coupling between adjacent pyramids and vertical coupling between alternating layers are proven to be key parameters for tuning of plasmon hybridization. Following optimization, the operational bandwidth of Au/Ge pyramids, i.e. the bandwidth within which absorption is higher than 90%, extends over a 0.2-5.8 µm wavelength range, i.e. from UV-visible to mid-infrared, and total absorption (integrated over the operational bandwidth) amounts to 98.0%. The omni-directional and polarization-independent high-absorption properties of the device are verified. Moreover, we show that the choice of the dielectric layer material (Si versus Ge) is not critical for achieving ultra-broadband characteristics, which confers versatility for both design and fabrication. Realistic fabrication scenarios are briefly discussed. This plasmon hybridization route could be useful in developing photothermal devices, thermal emitters or shielding devices that dissimulate objects from near infrared detectors.
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Sarrazin M, Herman A, Deparis O. First-principle calculation of solar cell efficiency under incoherent illumination. Opt Express 2013; 21 Suppl 4:A616-A630. [PMID: 24104489 DOI: 10.1364/oe.21.00a616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Because of the temporal incoherence of sunlight, solar cells efficiency should depend on the degree of coherence of the incident light. However, numerical computation methods, which are used to optimize these devices, fundamentally consider fully coherent light. Hereafter, we show that the incoherent efficiency of solar cells can be easily analytically calculated. The incoherent efficiency is simply derived from the coherent one thanks to a convolution product with a function characterizing the incoherent light. Our approach is neither heuristic nor empiric but is deduced from first-principle, i.e. Maxwell's equations. Usually, in order to reproduce the incoherent behavior, statistical methods requiring a high number of numerical simulations are used. With our method, such approaches are not required. Our results are compared with those from previous works and good agreement is found.
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Mouchet S, Colomer JF, Vandenbem C, Deparis O, Vigneron JP. Method for modeling additive color effect in photonic polycrystals with form anisotropic elements: the case of Entimus imperialis weevil. Opt Express 2013; 21:13228-13240. [PMID: 23736577 DOI: 10.1364/oe.21.013228] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The calculation of the reflectance of photonic crystals having form-birefringent anisotropic elements in the crystal unit cell, such as cylinders, often turns out to be problematic, especially when the reflectance spectrum has to be computed according to different crystal orientations as in polycrystals for instance. The method we propose here solves this problem in the specific case of photonic crystals whose periodicities are such that there are no diffraction orders except Bragg reflection in the visible range. For a given crystal orientation, the crystal is sliced into layers and the periodic spatial variations of the dielectric function ε are homogenized. Thanks to that homogenization, the calculation can be performed using standard thin film computation codes. In order to demonstrate the usefulness of our method, we applied it to the case of a natural photonic polycrystal found on the cuticle of Entimus imperialis weevil which is a remarkable example of additive color effect. Although each photonic crystal grain of the polycrystal produces a single bright iridescent color, a non-iridescent green matt coloration is perceived by the human eye due to multiscale averaging effects.
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Deparis O, El Daif O. Optimization of slow light one-dimensional Bragg structures for photocurrent enhancement in solar cells. Opt Lett 2012; 37:4230-4232. [PMID: 23073420 DOI: 10.1364/ol.37.004230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In 1D photonic crystal Bragg structures, strong localization of the light occurs in the high refractive index layers at wavelengths on the red edge of the photonic bandgap. We exploit this slow light effect for thin film solar cells in order to increase the absorption of light in silicon, as the latter has a high refractive index. Amorphous silicon and a transparent conductive oxide are chosen as high-index and low-index materials, respectively. Reference thin film cells have equivalent total thickness of amorphous silicon, plus antireflection coating and optional metallic back mirror. Through transfer-matrix calculations, we demonstrate that the spectrally integrated photon flux absorbed in active layers, hence the photocurrent, is enhanced by at least 10% with respect to reference using only a few periods. The enhancement is robust with respect to the light incidence angle. The key of such an enhancement is the tuning of the red edge to both the solar irradiance spectrum and the intrinsic material absorption spectrum, which is achieved by suitably selecting the layer thicknesses.
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Affiliation(s)
- Olivier Deparis
- Solid-State Physics Laboratory, University of Namur (FUNDP), 61 rue de Bruxelles, B-5000 Namur, Belgium.
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Ghazzal MN, Deparis O, Errachid A, Kebaili H, Simonis P, Eloy P, Vigneron JP, De Coninck J, Gaigneaux EM. Porosity control and surface sensitivity of titania/silica mesoporous multilayer coatings: applications to optical Bragg resonance tuning and molecular sensing. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm35107b] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Deparis O. Poynting vector in transfer-matrix formalism for the calculation of light absorption profile in stratified isotropic optical media. Opt Lett 2011; 36:3960-3962. [PMID: 22002352 DOI: 10.1364/ol.36.003960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In spite of the fact that solutions to Maxwell's equations in stratified isotropic optical media are well known, it appears that an explicit expression of the Poynting vector flux spatial evolution inside such a medium has not been derived so far. Based on exact electromagnetic field solutions in the transfer-matrix formalism, I derive such an expression and show that, due to the presence of counterpropagating waves in the medium, an additional contribution to the flux appears that exists only in optically absorbing layers and arises from the interference between these waves. Based on this theory, the concept of incremental absorption is introduced for the calculation of the light absorption profile along the stratification direction. As an illustration of this concept, absorption profiles in a Si-based thin-film tandem solar cell are predicted at typical wavelengths.
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Affiliation(s)
- Olivier Deparis
- Solid-State Physics Laboratory, Facultés Universitaires Notre-Dame de la Paix (FUNDP), Namur, Belgium.
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Deparis O, Beresna M, Vandenbem C, Kazansky PG. Light coupling and enhanced backscattering in layered plasmonic nanocomposites. Opt Express 2011; 19:1335-1343. [PMID: 21263674 DOI: 10.1364/oe.19.001335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Peculiar enhanced backscattering of light as well as selective vapor sensing were recently observed in a layered plasmonic nanocomposite which consisted of gold nanospheres randomly distributed in a sol-gel glass thin film on top of a soda-lime glass substrate, including a buried leaky waveguide. In order to understand the underlying physical mechanisms, we performed three-dimensional transfer-matrix numerical simulations and calculated the reflectance in both backward and specular directions as functions of the incidence angle. First, assuming a layered periodic particle arrangement, we confirmed that backscattering took place at grazing incidence if the spatial period in the layers was chosen within an optimal range, in agreement with theoretical predictions. Then, using a pseudo-random particle arrangement to describe the actual nanocomposite, we revealed that strong backscattering could nevertheless persist for specific particle distributions, in spite of their randomness. This behavior was tentatively explained by putting backscattering in relation with the particle interdistance statistics. Finally, we showed that backscattered reflectance was much more sensitive than specular reflectance to the adsorption of water vapor either on the surface or inside the likely porous structure of the glass host.
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Affiliation(s)
- Olivier Deparis
- Solid-State Physics Laboratory, University of Namur (FUNDP), Namur, Belgium.
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Ingram AL, Deparis O, Boulenguez J, Kennaway G, Berthier S, Parker AR. Structural origin of the green iridescence on the chelicerae of the red-backed jumping spider, Phidippus johnsoni (Salticidae: Araneae). Arthropod Struct Dev 2011; 40:21-5. [PMID: 20696270 DOI: 10.1016/j.asd.2010.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 06/08/2010] [Accepted: 07/28/2010] [Indexed: 05/16/2023]
Abstract
The structurally coloured chelicerae of jumping spiders (Salticidae) display some of the most striking of all colours in this family, in which they predominantly occur. Remarkably, however, the source of this iridescence has not been studied. For this reason, we chose to investigate the green iridescent chelicerae of the red-backed jumping spider, Phidippus johnsoni. The colour is restricted to the dorsal region of the basal chelicera segment--the paturon. This was confirmed by reflectance measurements taken at normal incidence and in backscatter, which gave a peak reflectance in the green (520 nm), arising from the first harmonic of a Bragg resonance in the near infrared. Transmission electron microscope analysis of the paturon cuticle revealed a stack of 86 layers of alternating low and high density materials, identified as air and chitin respectively. Simulations based on a periodic multilayer model of the ten outermost layers of this structure gave theoretical reflectance spectra, closely matching those observed, suggesting that the stack functions as a multilayer reflector for green. The colour is thought to function as a conspecific signal, since studies of vision in a closely related species, also displaying green chelicerae, have shown that the eyes have a peak spectral sensitivity, matching that of the chelicerae.
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Affiliation(s)
- A L Ingram
- Dept. of Zoology, Natural History Museum, Cromwell Road, South Kensington, London, UK.
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Beresna M, Kazansky PG, Deparis O, Carvalho ICS, Takahashi S, Zayats AV. Poling-assisted fabrication of plasmonic nanocomposite devices in glass. Adv Mater 2010; 22:4368-4372. [PMID: 20652902 DOI: 10.1002/adma.201001222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We report on the fabrication and optical properties of large-scale plasmonic nanocomposite metamaterial directly within glass matrix by thermal electric-field poling of glass. The achieved structure exhibits an enhanced backscattering (see Figure), which has strong dependence on the exposure of the surface to different organic vapors and can be used for development of new sensing platforms.
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Affiliation(s)
- Martynas Beresna
- Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK
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Rassart M, Simonis P, Bay A, Deparis O, Vigneron JP. Scale coloration change following water absorption in the beetle Hoplia coerulea (Coleoptera). Phys Rev E Stat Nonlin Soft Matter Phys 2009; 80:031910. [PMID: 19905149 DOI: 10.1103/physreve.80.031910] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Indexed: 05/28/2023]
Abstract
The blue scales on the cuticle of the male beetle Hoplia coerulea can absorb water, with the consequence that these scales, which have been shown to be responsible for the beetle's bright blue coloration, reversibly turn to emerald green with increasing water contents. Optical measurements are shown, by analytic photonic-crystal models, to be compatible with the full filling of the scales structures with water. The natural mechanism shows the way to produce a very efficient hygrochromic material: a medium which significantly changes color when its water contents are modified.
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Affiliation(s)
- Marie Rassart
- Research Center in Physics of Matter and Radiation, University of Namur (FUNDP), 61 rue de Bruxelles, B-5000 Namur, Belgium.
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Deparis O, Khuzayim N, Parker A, Vigneron JP. Assessment of the antireflection property of moth wings by three-dimensional transfer-matrix optical simulations. Phys Rev E Stat Nonlin Soft Matter Phys 2009; 79:041910. [PMID: 19518259 DOI: 10.1103/physreve.79.041910] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 03/12/2009] [Indexed: 05/27/2023]
Abstract
The wings of the moth Cacostatia ossa (Ctenuchinae) are covered on both sides by non-close-packed nipple arrays which are known to act as broadband antireflection coatings. Experimental evaluation of the antireflection property of these biological structures is problematic because of the lack of a proper reference for reflectance measurements, i.e., a smooth surface made of the same material as the wing. Theoretical evaluation, on the other hand, is much more reliable provided that optical simulations are carried out on a realistic structural model of the wing. Based on detailed morphological characterizations, we established a three-dimensional (3D) model of the wing and used 3D transfer-matrix optical simulations in order to demonstrate the broadband antireflection property of the wings of Cacostatia ossa. Differences between hemispherical and specular reflectance spectra revealed that diffraction effects were not negligible for this structure although they did not jeopardize the antireflection efficiency. The influences of the backside corrugation and of the material's absorption on the reflectance spectrum were also studied. In addition, simulations based on an effective-medium model of the wing were carried out using a multilayer thin-film code. In comparison with the latter simulations, the 3D transfer-matrix simulations were found to be more accurate for evaluating the antireflection property.
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Affiliation(s)
- Olivier Deparis
- Research center in Physics of Matter and Radiation, University of Namur, 61 rue de Bruxelles, B-5000 Namur, Belgium.
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Gaillot DP, Deparis O, Welch V, Wagner BK, Vigneron JP, Summers CJ. Composite organic-inorganic butterfly scales: production of photonic structures with atomic layer deposition. Phys Rev E Stat Nonlin Soft Matter Phys 2008; 78:031922. [PMID: 18851080 DOI: 10.1103/physreve.78.031922] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Indexed: 05/26/2023]
Abstract
Recent advances in the photonics and optics industries have produced great demand for ever more sophisticated optical devices, such as photonic crystals. However, photonic crystals are notoriously difficult to manufacture. Increasingly, therefore, researchers have turned towards naturally occurring photonic structures for inspiration and a wide variety of elaborate techniques have been attempted to copy and harness biological processes to manufacture artificial photonic structures. Here, we describe a simple, direct process for producing an artificial photonic device by using a naturally occurring structure from the wings of the butterfly Papilio blumei as a template and low-temperature atomic layer deposition of TiO2 to create a faithful cast of the structure. The optical properties of the organic-inorganic diffraction structures produced are assessed by normal-incidence specular reflectance and found to be well described by multilayer computation method using a two-dimensional photonic crystal model. Depending on the structural integrity of the initially sealed scale, it was found possible not only to replicate the outer but also the inner and more complex surfaces of the structure, each resulting in distinct multicolor optical behavior as revealed by experimental and theoretical data. In this paper, we also explore tailoring the process to design composite skeleton architectures with desired optical properties and integrated multifunctional (mechanical, thermal, optical, fluidic) properties.
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Affiliation(s)
- Davy P Gaillot
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, USA.
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Vigneron JP, Pasteels JM, Windsor DM, Vértesy Z, Rassart M, Seldrum T, Dumont J, Deparis O, Lousse V, Biró LP, Ertz D, Welch V. Switchable reflector in the Panamanian tortoise beetle Charidotella egregia (Chrysomelidae: Cassidinae). Phys Rev E Stat Nonlin Soft Matter Phys 2007; 76:031907. [PMID: 17930271 DOI: 10.1103/physreve.76.031907] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2007] [Indexed: 05/15/2023]
Abstract
The tortoise beetle Charidotella egregia is able to modify the structural color of its cuticle reversibly, when disturbed by stressful external events. After field observations, measurements of the optical properties in the two main stable color states and scanning electron microscope and transmission electron microscope investigations, a physical mechanism is proposed to explain the color switching of this insect. It is shown that the gold coloration displayed by animals at rest arises from a chirped multilayer reflector maintained in a perfect coherent state by the presence of humidity in the porous patches within each layer, while the red color displayed by disturbed animals results from the destruction of this reflector by the expulsion of the liquid from the porous patches, turning the multilayer into a translucent slab that leaves an unobstructed view of the deeper-lying, pigmented red substrate. This mechanism not only explains the change of hue but also the change of scattering mode from specular to diffuse. Quantitative modeling is developed in support of this analysis.
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Affiliation(s)
- Jean Pol Vigneron
- Département de Physique, Facultés Universitaires Notre-Dame de la Paix, 61 rue de Bruxelles, B-5000 Namur, Belgium.
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Phan Huy K, Nguyen AT, Brainis E, Haelterman M, Emplit P, Corbari C, Canagasabey A, Kazansky PG, Deparis O, Fotiadi AA, Mégret P, Massar S. Photon pair source based on parametric fluorescence in periodically poled twin-hole silica fiber. Opt Express 2007; 15:4419-4426. [PMID: 19532689 DOI: 10.1364/oe.15.004419] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We present observations of quasi-phase matched parametric fluorescence in a periodically poled twin-hole silica fiber. The phase matching condition in the fiber enables the generation of a degenerate signal field in the fiber-optic communication band centered on 1556 nm. We performed coincidence measurements and a Hong-Ou-Mandel experiment to validate that the signal arises from photon pairs. A coincidence peak with a signal to noise ratio (SNR) of 4 using 43 mW of pump power and a Hong-Ou-Mandel dip showing 40% net visibility were measured. Moreover, the experiments were performed with standard single mode fibers spliced at both ends of the poled section, which makes this source easy to integrate in fiber-optic quantum communication applications.
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Affiliation(s)
- Kien Phan Huy
- Service d'Optique et Acoustique, Université Libre de Bruxelles, Avenue F.D. Roosevelt 50, CP 194/5, 1050 Bruxelles, Belgium.
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Welch V, Lousse V, Deparis O, Parker A, Vigneron JP. Orange reflection from a three-dimensional photonic crystal in the scales of the weevil Pachyrrhynchus congestus pavonius (Curculionidae). Phys Rev E Stat Nonlin Soft Matter Phys 2007; 75:041919. [PMID: 17500933 DOI: 10.1103/physreve.75.041919] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Indexed: 05/15/2023]
Abstract
The three-dimensional structure that causes the coloration of the tropical weevil Pachyrrhynchus congestus pavonius was studied, using a combination of electron microscopy, optical spectroscopy, and numerical modeling. The orange scales that cover the colored rings on the animal's body were opened, to display the structure responsible for the coloration. This structure is a three-dimensional photonic polycrystal, each grain of which showing a face-centered cubic symmetry. The measured lattice parameter and the observed filling fraction of this structure explain the dominant reflected wavelength in the reddish orange. The long-range disorder introduced by the grain boundaries explains the paradoxical observation that the reflectance, although generated by a photonic crystal, is insensitive to changes in the viewing angle.
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Affiliation(s)
- Victoria Welch
- Laboratoire de Physique du Solide, Facultés Universitaires Notre-Dame de la Paix, 61 rue de Bruxelles, B-5000 Namur, Belgium
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Deparis O, Vandenbem C, Vigneron JP. Wide angular range operation of a dielectric multilayer film with a photonic-crystal-type defect. Opt Lett 2007; 32:686-8. [PMID: 17308602 DOI: 10.1364/ol.32.000686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Light can tunnel through a high-reflectivity dielectric multilayer film when a photonic-crystal-type defect is introduced in the structure, which is useful for optical signal processing. We consider chirped structures with a defect in layer thickness for which high reflectivity is achieved over a broad wavelength range except within a narrow spectral window. The useful transmission window, while it shifts toward shorter wavelengths as the angle of incidence of the light beam is increased, does not, in general, survive; i.e., transmission disappears progressively. We show that wide angular range operation can, however, be achieved by a proper design of the chirped structure. Analytical expressions for the design parameters are derived on the basis of a semi-infinite photonic crystal model. Theoretical reflectance spectra of defect SiO2/TiO2 chirped multilayer films are presented and discussed in terms of the dispersion of the electromagnetic radiation modes of the finite photonic crystal. These devices offer a simple way to mechanically tune (through inclination of the film) the wavelength transmitted from a fixed white-light beam.
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Affiliation(s)
- Olivier Deparis
- Laboratoire de Physique du Solide, Facultés Universitaires Notre-Dame de la Paix, Namur, Belgium.
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Deparis O, Vandenbem C, Rassart M, Welch V, Vigneron JP. Color-selecting reflectors inspired from biological periodic multilayer structures. Opt Express 2006; 14:3547-3555. [PMID: 19516501 DOI: 10.1364/oe.14.003547] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We propose a semi-infinite 1-D photonic crystal approach for designing artificial reflectors which aim to reproduce color changes with the angle of incidence found in biological periodic multilayer templates. We show that both the dominant reflected wavelength and the photonic bandgap can be predicted and that these predictions agree with exact calculations of reflectance spectra for a finite multilayer structure. In order to help the designer, the concept of spectral richness of angle-tuned color-selecting reflectors is introduced and color changes with angle are displayed in a chromaticity diagram. The usefulness of the photonic crystal approach is demonstrated by modelling a biological template (found in the cuticle of Chrysochora vittata beetle) and by designing a bio-inspired artificial reflector which reproduces the visual aspect of the template. The bioinspired novel aspect of the design relies on the strong unbalance between the thicknesses of the two layers forming the unit cell.
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Vigneron JP, Rassart M, Vandenbem C, Lousse V, Deparis O, Biró LP, Dedouaire D, Cornet A, Defrance P. Spectral filtering of visible light by the cuticle of metallic woodboring beetles and microfabrication of a matching bioinspired material. Phys Rev E Stat Nonlin Soft Matter Phys 2006; 73:041905. [PMID: 16711834 DOI: 10.1103/physreve.73.041905] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Revised: 01/30/2006] [Indexed: 05/09/2023]
Abstract
Samples of the cuticle taken from the body of Buprestidae Chrysochroa vittata have been studied by scanning electron microscopy and optical reflectance measurements, related to numerical simulations. The cause of the metallic coloration of the body of these insects is determined to be the structure of the hard carapace constructed as a stack of thin chitin layers separated by very thin irregular air gaps. In particular the change of color as a function of the observation angle is elucidated in terms of an infinite photonic-crystal model, confirmed by finite multilayer calculations. These mechanisms are used to develop an artificial bioinspired multilayer system which reproduces the visual effects provided by the insect surface.
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Affiliation(s)
- Jean Pol Vigneron
- Laboratoire de Physique du Solide, Facultés Universitaires Notre-Dame de la Paix, rue de Bruxelles 61, B-5000 Namur, Belgium.
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Abdolvand A, Podlipensky A, Seifert G, Graener H, Deparis O, Kazansky P. Electric field-assisted formation of percolated silver nanolayers inside glass. Opt Express 2005; 13:1266-1274. [PMID: 19494999 DOI: 10.1364/opex.13.001266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A combination of direct current (d.c.) electric field and moderately elevated temperature is applied to a glass with embedded spherical silver nanoparticles in the near surface region. The field-assisted dissolution of silver nanoparticles leads to the formation of a layer of percolated silver clusters with modified optical properties beneath the glass surface. The distance between this produced buried layer and the surface of the sample can be controlled by the magnitude of the applied voltage. The same holds for the interferential colors observable in reflection. The presented technique is easy to implement and paves a route towards the engineering of the optical properties of metal-doped nanocomposite glasses via modification of the spatial distribution of metallic inclusions.
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Podlipensky A, Abdolvand A, Seifert G, Graener H, Deparis O, Kazansky PG. Dissolution of Silver Nanoparticles in Glass through an Intense dc Electric Field. J Phys Chem B 2004. [DOI: 10.1021/jp045874c] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A. Podlipensky
- Physics Department, Martin-Luther-University Halle-Wittenberg, D-06099 Halle, Germany, and Optoelectronics Research Centre, University of Southampton, SO17 1BJ, United Kingdom
| | - A. Abdolvand
- Physics Department, Martin-Luther-University Halle-Wittenberg, D-06099 Halle, Germany, and Optoelectronics Research Centre, University of Southampton, SO17 1BJ, United Kingdom
| | - G. Seifert
- Physics Department, Martin-Luther-University Halle-Wittenberg, D-06099 Halle, Germany, and Optoelectronics Research Centre, University of Southampton, SO17 1BJ, United Kingdom
| | - H. Graener
- Physics Department, Martin-Luther-University Halle-Wittenberg, D-06099 Halle, Germany, and Optoelectronics Research Centre, University of Southampton, SO17 1BJ, United Kingdom
| | - O. Deparis
- Physics Department, Martin-Luther-University Halle-Wittenberg, D-06099 Halle, Germany, and Optoelectronics Research Centre, University of Southampton, SO17 1BJ, United Kingdom
| | - P. G. Kazansky
- Physics Department, Martin-Luther-University Halle-Wittenberg, D-06099 Halle, Germany, and Optoelectronics Research Centre, University of Southampton, SO17 1BJ, United Kingdom
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Sciamanna M, Rogister F, Deparis O, Mégret P, Blondel M, Erneux T. Bifurcation to polarization self-modulation in vertical-cavity surface-emitting lasers: errata. Opt Lett 2002; 27:875. [PMID: 18007957 DOI: 10.1364/ol.27.000875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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Sciamanna M, Rogister F, Deparis O, Mégret P, Blondel M, Erneux T. Bifurcation to polarization self-modulation in vertical-cavity surface-emitting lasers. Opt Lett 2002; 27:261-263. [PMID: 18007773 DOI: 10.1364/ol.27.000261] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Experiments have yielded polarization self-modulation in vertical-cavity surface-emitting lasers (VCSELs) subject to a pi/2 polarization-rotating optical feedback. The phenomenon has been simulated numerically, but its bifurcation has never been explained. We show that polarization self-modulation results from a Hopf bifurcation mechanism that can be analyzed in terms of the laser feedback parameters. Our analysis predicts other bifurcations for low values of the feedback rate, which explain why more-complex time-dependent outputs have been observed as alternatives to polarization self-modulation.
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Fotiadi AA, Kiyan R, Deparis O, Mégret P, Blondel M. Statistical properties of stimulated Brillouin scattering in single-mode optical fibers above threshold. Opt Lett 2002; 27:83-85. [PMID: 18007719 DOI: 10.1364/ol.27.000083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We performed numerical simulations to obtain statistical and spectral characteristics of stimulated Brillouin scattering (SBS) initiated by Gaussian noise in single-mode optical fibers. Recently published experimental spectra of SBS power [e.g., Phys. Rev. Lett. 85, 1879 (2000)] are explained completely by a one-dimensional SBS model. We give a clear physical insight into the problem and, for what is to our knowledge the first time, reveal how the probability function of Stokes power, the power-correlation function, and the SBS spectra evolve as key parameters of the model vary, leading to a modification of Stokes field statistics.
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Pottiez O, Deparis O, Kiyan R, Mégret P, Blondel M. Measurement of pulse width and amplitude jitter noises of gigahertz optical pulse trains by time-domain demodulation. Opt Lett 2001; 26:1779-1781. [PMID: 18059696 DOI: 10.1364/ol.26.001779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We propose a technique for measuring both pulse width and amplitude jitter noises of high-repetition-rate optical pulse trains and the cross correlation between these noises as well. The technique is based on time-domain amplitude demodulation of three harmonic components of the detected pulse train. We applied this technique to characterize noises of a gigahertz optical pulse train generated by an actively mode-locked Er-doped fiber laser. Correlation between pulse width jitter and pulse amplitude jitter was observed at low frequencies in this laser. Unlike relaxation oscillation noise, low-frequency noise is free from pulse energy jitter. Owing to its ability to measure pulse width jitter in addition to amplitude and phase jitters, this technique is of great interest for characterizing noises of a wide variety of optical pulse train sources.
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Rogister F, Locquet A, Pieroux D, Sciamanna M, Deparis O, Mégret P, Blondel M. Secure communication scheme using chaotic laser diodes subject to incoherent optical feedback and incoherent optical injection. Opt Lett 2001; 26:1486-1488. [PMID: 18049643 DOI: 10.1364/ol.26.001486] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We propose a secure communication scheme based on anticipating synchronization of two chaotic laser diodes, one subject to incoherent optical feedback and the other to incoherent optical injection. This scheme does not require fine tuning of the optical frequencies of both lasers as is the case for other schemes based on chaotic laser diodes subject to coherent optical feedback and injection. Our secure communication scheme is therefore attractive for experimental investigation.
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