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Vidal C, Tilmann B, Tiwari S, Raziman TV, Maier SA, Wenger J, Sapienza R. Fluorescence Enhancement in Topologically Optimized Gallium Phosphide All-Dielectric Nanoantennas. NANO LETTERS 2024; 24:2437-2443. [PMID: 38354357 PMCID: PMC10905999 DOI: 10.1021/acs.nanolett.3c03773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 02/16/2024]
Abstract
Nanoantennas capable of large fluorescence enhancement with minimal absorption are crucial for future optical technologies from single-photon sources to biosensing. Efficient dielectric nanoantennas have been designed, however, evaluating their performance at the individual emitter level is challenging due to the complexity of combining high-resolution nanofabrication, spectroscopy and nanoscale positioning of the emitter. Here, we study the fluorescence enhancement in infinity-shaped gallium phosphide (GaP) nanoantennas based on a topologically optimized design. Using fluorescence correlation spectroscopy (FCS), we probe the nanoantennas enhancement factor and observe an average of 63-fold fluorescence brightness enhancement with a maximum of 93-fold for dye molecules in nanogaps between 20 and 50 nm. The experimentally determined fluorescence enhancement of the nanoantennas is confirmed by numerical simulations of the local density of optical states (LDOS). Furthermore, we show that beyond design optimization of dielectric nanoantennas, increased performances can be achieved via tailoring of nanoantenna fabrication.
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Affiliation(s)
- Cynthia Vidal
- Blackett
Laboratory, Department of Physics, Imperial
College London, London SW7 2AZ, U.K.
| | - Benjamin Tilmann
- Nano-Institute
Munich, Department of Physics, Ludwig-Maximilians-University
Munich, 80539 Munich, Germany
| | - Sunny Tiwari
- Aix
Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, 13013 Marseille, France
| | - T. V. Raziman
- Blackett
Laboratory, Department of Physics, Imperial
College London, London SW7 2AZ, U.K.
- Department
of Mathematics, Imperial College London, London SW7 2AZ, U.K.
| | - Stefan A. Maier
- Blackett
Laboratory, Department of Physics, Imperial
College London, London SW7 2AZ, U.K.
- School
of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia
| | - Jérôme Wenger
- Aix
Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, 13013 Marseille, France
| | - Riccardo Sapienza
- Blackett
Laboratory, Department of Physics, Imperial
College London, London SW7 2AZ, U.K.
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2
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Babar AN, Weis TAS, Tsoukalas K, Kadkhodazadeh S, Arregui G, Vosoughi Lahijani B, Stobbe S. Self-assembled photonic cavities with atomic-scale confinement. Nature 2023; 624:57-63. [PMID: 38057568 PMCID: PMC10700130 DOI: 10.1038/s41586-023-06736-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 10/10/2023] [Indexed: 12/08/2023]
Abstract
Despite tremendous progress in research on self-assembled nanotechnological building blocks, such as macromolecules1, nanowires2 and two-dimensional materials3, synthetic self-assembly methods that bridge the nanoscopic to macroscopic dimensions remain unscalable and inferior to biological self-assembly. By contrast, planar semiconductor technology has had an immense technological impact, owing to its inherent scalability, yet it seems unable to reach the atomic dimensions enabled by self-assembly. Here, we use surface forces, including Casimir-van der Waals interactions4, to deterministically self-assemble and self-align suspended silicon nanostructures with void features well below the length scales possible with conventional lithography and etching5, despite using only conventional lithography and etching. The method is remarkably robust and the threshold for self-assembly depends monotonically on all the governing parameters across thousands of measured devices. We illustrate the potential of these concepts by fabricating nanostructures that are impossible to make with any other known method: waveguide-coupled high-Q silicon photonic cavities6,7 that confine telecom photons to 2 nm air gaps with an aspect ratio of 100, corresponding to mode volumes more than 100 times below the diffraction limit. Scanning transmission electron microscopy measurements confirm the ability to build devices with sub-nanometre dimensions. Our work constitutes the first steps towards a new generation of fabrication technology that combines the atomic dimensions enabled by self-assembly with the scalability of planar semiconductors.
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Affiliation(s)
- Ali Nawaz Babar
- DTU Electro, Department of Electrical and Photonics Engineering, Technical University of Denmark, Kongens Lyngby, Denmark.
- NanoPhoton - Center for Nanophotonics, Technical University of Denmark, Kongens Lyngby, Denmark.
| | - Thor August Schimmell Weis
- DTU Electro, Department of Electrical and Photonics Engineering, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Konstantinos Tsoukalas
- DTU Electro, Department of Electrical and Photonics Engineering, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Shima Kadkhodazadeh
- NanoPhoton - Center for Nanophotonics, Technical University of Denmark, Kongens Lyngby, Denmark
- DTU Nanolab, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Guillermo Arregui
- DTU Electro, Department of Electrical and Photonics Engineering, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Babak Vosoughi Lahijani
- DTU Electro, Department of Electrical and Photonics Engineering, Technical University of Denmark, Kongens Lyngby, Denmark
- NanoPhoton - Center for Nanophotonics, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Søren Stobbe
- DTU Electro, Department of Electrical and Photonics Engineering, Technical University of Denmark, Kongens Lyngby, Denmark.
- NanoPhoton - Center for Nanophotonics, Technical University of Denmark, Kongens Lyngby, Denmark.
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3
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Bongard J, Levin M. There’s Plenty of Room Right Here: Biological Systems as Evolved, Overloaded, Multi-Scale Machines. Biomimetics (Basel) 2023; 8:biomimetics8010110. [PMID: 36975340 PMCID: PMC10046700 DOI: 10.3390/biomimetics8010110] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/24/2023] [Accepted: 03/01/2023] [Indexed: 03/18/2023] Open
Abstract
The applicability of computational models to the biological world is an active topic of debate. We argue that a useful path forward results from abandoning hard boundaries between categories and adopting an observer-dependent, pragmatic view. Such a view dissolves the contingent dichotomies driven by human cognitive biases (e.g., a tendency to oversimplify) and prior technological limitations in favor of a more continuous view, necessitated by the study of evolution, developmental biology, and intelligent machines. Form and function are tightly entwined in nature, and in some cases, in robotics as well. Thus, efforts to re-shape living systems for biomedical or bioengineering purposes require prediction and control of their function at multiple scales. This is challenging for many reasons, one of which is that living systems perform multiple functions in the same place at the same time. We refer to this as “polycomputing”—the ability of the same substrate to simultaneously compute different things, and make those computational results available to different observers. This ability is an important way in which living things are a kind of computer, but not the familiar, linear, deterministic kind; rather, living things are computers in the broad sense of their computational materials, as reported in the rapidly growing physical computing literature. We argue that an observer-centered framework for the computations performed by evolved and designed systems will improve the understanding of mesoscale events, as it has already done at quantum and relativistic scales. To develop our understanding of how life performs polycomputing, and how it can be convinced to alter one or more of those functions, we can first create technologies that polycompute and learn how to alter their functions. Here, we review examples of biological and technological polycomputing, and develop the idea that the overloading of different functions on the same hardware is an important design principle that helps to understand and build both evolved and designed systems. Learning to hack existing polycomputing substrates, as well as to evolve and design new ones, will have massive impacts on regenerative medicine, robotics, and computer engineering.
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Affiliation(s)
- Joshua Bongard
- Department of Computer Science, University of Vermont, Burlington, VT 05405, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, 200 Boston Ave., Suite 4600, Medford, MA 02155, USA
- Correspondence: ; Tel.: +(617)-627-6161
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4
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Kountouris G, Mørk J, Denning EV, Kristensen PT. Modal properties of dielectric bowtie cavities with deep sub-wavelength confinement. OPTICS EXPRESS 2022; 30:40367-40378. [PMID: 36298971 DOI: 10.1364/oe.472793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 10/09/2022] [Indexed: 06/16/2023]
Abstract
We present a design for an optical dielectric bowtie cavity which features deep sub-wavelength confinement of light. The cavity is derived via simplification of a complex geometry identified through inverse design by topology optimization, and it successfully retains the extreme properties of the original structure, including an effective mode volume of Veff = 0.083 ± 0.001 (λc/2nSi)3 at its center. Based on this design, we present a modal analysis to show that the Purcell factor can be well described by a single quasinormal mode in a wide bandwidth of interest. Owing to the small mode volume, moreover, the cavity exhibits a remarkable sensitivity to local shape deformations, which we show to be well described by perturbation theory. The intuitive simplification approach to inverse design geometries coupled with the quasinormal mode analysis demonstrated in this work provides a powerful modeling framework for the emerging field of dielectric cavities with deep sub-wavelength confinement.
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5
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Nanometer-scale photon confinement in topology-optimized dielectric cavities. Nat Commun 2022; 13:6281. [PMID: 36271087 PMCID: PMC9587274 DOI: 10.1038/s41467-022-33874-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 10/06/2022] [Indexed: 11/08/2022] Open
Abstract
Nanotechnology enables in principle a precise mapping from design to device but relied so far on human intuition and simple optimizations. In nanophotonics, a central question is how to make devices in which the light-matter interaction strength is limited only by materials and nanofabrication. Here, we integrate measured fabrication constraints into topology optimization, aiming for the strongest possible light-matter interaction in a compact silicon membrane, demonstrating an unprecedented photonic nanocavity with a mode volume of V ~ 3 × 10-4 λ3, quality factor Q ~ 1100, and footprint 4 λ2 for telecom photons with a λ ~ 1550 nm wavelength. We fabricate the cavity, which confines photons inside 8 nm silicon bridges with ultra-high aspect ratios of 30 and use near-field optical measurements to perform the first experimental demonstration of photon confinement to a single hotspot well below the diffraction limit in dielectrics. Our framework intertwines topology optimization with fabrication and thereby initiates a new paradigm of high-performance additive and subtractive manufacturing.
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6
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Brûlé Y, Wiecha P, Cuche A, Paillard V, Colas des Francs G. Magnetic and electric Purcell factor control through geometry optimization of high index dielectric nanostructures. OPTICS EXPRESS 2022; 30:20360-20372. [PMID: 36224783 DOI: 10.1364/oe.460168] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/17/2022] [Indexed: 06/16/2023]
Abstract
We design planar silicon antennas for controlling the emission rate of magnetic or electric dipolar emitters. Evolutionary algorithms coupled to the Green Dyadic Method lead to different optimized geometries which depend on the nature and orientation of the dipoles. We discuss the physical origin of the obtained configurations thanks to modal analysis but also emphasize the role of nanoscale design of the LDOS. We complete our study using finite element method and demonstrate an enhancement up to 2 × 103 of the magnetic Purcell factor in europium ions. Our work brings together random optimizations to explore geometric parameters without constraint, a first order deterministic approach to understand the optimized designs and a modal analysis which clarifies the physical origin of the exaltation of the magnetic Purcell effect.
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7
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Albrechtsen M, Vosoughi Lahijani B, Stobbe S. Two regimes of confinement in photonic nanocavities: bulk confinement versus lightning rods. OPTICS EXPRESS 2022; 30:15458-15469. [PMID: 35473265 DOI: 10.1364/oe.448929] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 04/07/2022] [Indexed: 06/14/2023]
Abstract
We present a theoretical study of dielectric bowtie cavities and show that they are governed by two essentially different confinement regimes. The first is confinement inside the bulk dielectric and the second is a local lightning-rod regime where the field is locally enhanced at sharp corners and may yield a vanishing mode volume without necessarily enhancing the mode inside the bulk dielectric. We show that while the bulk regime is reminiscent of the confinement in conventional nanocavities, the most commonly used definition of the mode volume gauges in fact the lightning-rod effect when applied to ultra-compact cavities, such as bowties. Distinguishing between these two regimes will be crucial for future research on nanocavities, and our insights show how to obtain strongly enhanced light-matter interaction over large bandwidths.
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8
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Barry MA, Berthier V, Wilts BD, Cambourieux MC, Bennet P, Pollès R, Teytaud O, Centeno E, Biais N, Moreau A. Evolutionary algorithms converge towards evolved biological photonic structures. Sci Rep 2020; 10:12024. [PMID: 32694514 PMCID: PMC7374560 DOI: 10.1038/s41598-020-68719-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 06/22/2020] [Indexed: 11/09/2022] Open
Abstract
Nature features a plethora of extraordinary photonic architectures that have been optimized through natural evolution in order to more efficiently reflect, absorb or scatter light. While numerical optimization is increasingly and successfully used in photonics, it has yet to replicate any of these complex naturally occurring structures. Using evolutionary algorithms inspired by natural evolution and performing particular optimizations (maximize reflection for a given wavelength, for a broad range of wavelength or maximize the scattering of light), we have retrieved the most stereotypical natural photonic structures. Whether those structures are Bragg mirrors, chirped dielectric mirrors or the gratings on top of Morpho butterfly wings, our results indicate how such regular structures might have spontaneously emerged in nature and to which precise optical or fabrication constraints they respond. Comparing algorithms show that recombination between individuals, inspired by sexual reproduction, confers a clear advantage that can be linked to the fact that photonic structures are fundamentally modular: each part of the structure has a role which can be understood almost independently from the rest. Such an in silico evolution also suggests original and elegant solutions to practical problems, as illustrated by the design of counter-intuitive anti-reflective coatings for solar cells.
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Affiliation(s)
- Mamadou Aliou Barry
- Université Clermont Auvergne, CNRS, Sigma Clermont, Institut Pascal, 63000, Clermont-Ferrand, France
| | - Vincent Berthier
- TAO, Inria, LRI, Université Paris Sud CNRS UMR 6823, Orsay Cedex, France
| | - Bodo D Wilts
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700, Fribourg, Switzerland
| | - Marie-Claire Cambourieux
- Université Clermont Auvergne, CNRS, Sigma Clermont, Institut Pascal, 63000, Clermont-Ferrand, France
| | - Pauline Bennet
- Université Clermont Auvergne, CNRS, Sigma Clermont, Institut Pascal, 63000, Clermont-Ferrand, France
| | - Rémi Pollès
- Université Clermont Auvergne, CNRS, Sigma Clermont, Institut Pascal, 63000, Clermont-Ferrand, France
| | - Olivier Teytaud
- TAO, Inria, LRI, Université Paris Sud CNRS UMR 6823, Orsay Cedex, France.,Facebook AI Research, 6 rue Menars, 75000, Paris, France
| | - Emmanuel Centeno
- Université Clermont Auvergne, CNRS, Sigma Clermont, Institut Pascal, 63000, Clermont-Ferrand, France
| | - Nicolas Biais
- Graduate Center of CUNY and Department of Biology, CUNY Brooklyn College, New York, NY, 11210, USA
| | - Antoine Moreau
- Université Clermont Auvergne, CNRS, Sigma Clermont, Institut Pascal, 63000, Clermont-Ferrand, France.
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9
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Mignuzzi S, Vezzoli S, Horsley SAR, Barnes WL, Maier SA, Sapienza R. Nanoscale Design of the Local Density of Optical States. NANO LETTERS 2019; 19:1613-1617. [PMID: 30786717 DOI: 10.1021/acs.nanolett.8b04515] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We propose a design concept for tailoring the local density of optical states (LDOS) in dielectric nanostructures, based on the phase distribution of the scattered optical fields induced by point-like emitters. First we demonstrate that the LDOS can be expressed in terms of a coherent summation of constructive and destructive contributions. By using an iterative approach, dielectric nanostructures can be designed to effectively remove the destructive terms. In this way, dielectric Mie resonators, featuring low LDOS for electric dipoles, can be reshaped to enable enhancements of 3 orders of magnitude. To demonstrate the generality of the method, we also design nanocavities that enhance the radiated power of a circular dipole, a quadrupole, and an arbitrary collection of coherent dipoles. Our concept provides a powerful tool for high-performance dielectric resonators and affords fundamental insights into light-matter coupling at the nanoscale.
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Affiliation(s)
- Sandro Mignuzzi
- The Blackett Laboratory, Department of Physics , Imperial College London , London SW7 2BW , United Kingdom
| | - Stefano Vezzoli
- The Blackett Laboratory, Department of Physics , Imperial College London , London SW7 2BW , United Kingdom
| | - Simon A R Horsley
- Department of Physics and Astronomy , University of Exeter , Exeter EX4 4QL , United Kingdom
| | - William L Barnes
- Department of Physics and Astronomy , University of Exeter , Exeter EX4 4QL , United Kingdom
| | - Stefan A Maier
- The Blackett Laboratory, Department of Physics , Imperial College London , London SW7 2BW , United Kingdom
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics , Ludwig-Maxilimians-Universität München , München 80539 , Germany
| | - Riccardo Sapienza
- The Blackett Laboratory, Department of Physics , Imperial College London , London SW7 2BW , United Kingdom
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10
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Wang C, Yu S, Chen W, Sun C. Highly efficient light-trapping structure design inspired by natural evolution. Sci Rep 2013; 3:1025. [PMID: 23289067 PMCID: PMC3535673 DOI: 10.1038/srep01025] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 11/20/2012] [Indexed: 11/29/2022] Open
Abstract
Recent advances in nanophotonic light trapping open up the new gateway to enhance the absorption of solar energy beyond the so called Yablonovitch Limit. It addresses the urgent needs in developing low cost thin-film solar photovoltaic technologies. However, current design strategy mainly relies on the parametric approach that is subject to the predefined topological design concepts based on physical intuition. Incapable of dealing with the topological variation severely constrains the design of optimal light trapping structure. Inspired by natural evolution process, here we report a design framework driven by topology optimization based on genetic algorithms to achieve a highly efficient light trapping structure. It has been demonstrated that the optimal light trapping structures obtained in this study exhibit more than 3-fold increase over the Yablonovitch Limit with the broadband absorption efficiency of 48.1%, beyond the reach of intuitive designs.
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Affiliation(s)
- Chen Wang
- Mechanical Engineering Department, Northwestern University, Evanston, Illinois 60208, USA
- These authors contributed equally to this work
| | - Shuangcheng Yu
- Mechanical Engineering Department, Northwestern University, Evanston, Illinois 60208, USA
- These authors contributed equally to this work
| | - Wei Chen
- Mechanical Engineering Department, Northwestern University, Evanston, Illinois 60208, USA
| | - Cheng Sun
- Mechanical Engineering Department, Northwestern University, Evanston, Illinois 60208, USA
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11
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Lin C, Povinelli ML. Optimal design of aperiodic, vertical silicon nanowire structures for photovoltaics. OPTICS EXPRESS 2011; 19 Suppl 5:A1148-A1154. [PMID: 21935258 DOI: 10.1364/oe.19.0a1148] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We design a partially aperiodic, vertically-aligned silicon nanowire array that maximizes photovoltaic absorption. The optimal structure is obtained using a random walk algorithm with transfer matrix method based electromagnetic forward solver. The optimal, aperiodic structure exhibits a 2.35 times enhancement in ultimate efficiency compared to its periodic counterpart. The spectral behavior mimics that of a periodic array with larger lattice constant. For our system, we find that randomly-selected, aperiodic structures invariably outperform the periodic array.
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Affiliation(s)
- Chenxi Lin
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA, USA.
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12
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Arpin KA, Mihi A, Johnson HT, Baca AJ, Rogers JA, Lewis JA, Braun PV. Multidimensional architectures for functional optical devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2010; 22:1084-1101. [PMID: 20401933 DOI: 10.1002/adma.200904096] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Materials exhibiting multidimensional structure with characteristic lengths ranging from the nanometer to the micrometer scale have extraordinary potential for emerging optical applications based on the regulation of light-matter interactions via the mesoscale organization of matter. As the structural dimensionality increases, the opportunities for controlling light-matter interactions become increasingly diverse and powerful. Recent advances in multidimensional structures have been demonstrated that serve as the basis for three-dimensional photonic-bandgap materials, metamaterials, optical cloaks, highly efficient low-cost solar cells, and chemical and biological sensors. In this Review, the state-of-the-art design and fabrication of multidimensional architectures for functional optical devices are covered and the next steps for this important field are described.
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Affiliation(s)
- Kevin A Arpin
- Frederick Seitz Materials Research Laboratory 104 South Goodwin Ave Urbana, IL 61801, USA
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13
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Biró LP, Kertész K, Horváth E, Márk GI, Molnár G, Vértesy Z, Tsai JF, Kun A, Bálint Z, Vigneron JP. Bioinspired artificial photonic nanoarchitecture using the elytron of the beetle Trigonophorus rothschildi varians as a 'blueprint'. J R Soc Interface 2009; 7:887-94. [PMID: 19933221 DOI: 10.1098/rsif.2009.0438] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
An unusual, intercalated photonic nanoarchitecture was discovered in the elytra of Taiwanese Trigonophorus rothschildi varians beetles. It consists of a multilayer structure intercalated with a random distribution of cylindrical holes normal to the plane of the multilayer. The nanoarchitectures were characterized structurally by scanning electron microscopy and optically by normal incidence, integrated and goniometric reflectance measurements. They exhibit an unsaturated specular and saturated non-specular component of the reflected light. Bioinspired, artificial nanoarchitectures of similar structure and with similar properties were realized by drilling holes of submicron size in a multilayer structure, showing that such photonic nanoarchitectures of biological origin may constitute valuable blueprints for artificial photonic materials.
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Affiliation(s)
- L P Biró
- Research Institute for Technical Physics and Materials Science, PO Box 49, H-1525 Budapest, Hungary.
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14
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Fordell T, Miranda M, Persson A, L'Huillier A. Carrier-envelope phase stabilization of a multi-millijoule, regenerative-amplifier-based chirped-pulse smplifier system. OPTICS EXPRESS 2009; 17:21091-21097. [PMID: 19997348 DOI: 10.1364/oe.17.021091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This article reports on the successful stabilization of the carrier-envelope phase of a 1-kHz laser system that includes a large grating stretcher, a regenerative amplifier, a multipass amplifier and a grating compressor. Phase stability for pulse energies up to 6 mJ is demonstrated using electronic feedback to the oscillator locking electronics as well as feedback via an acousto-optic programmable dispersive filter.
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Affiliation(s)
- T Fordell
- 1 Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden.
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15
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Säynätjoki A, Alasaarela T, Khanna A, Karvonen L, Stenberg P, Kuittinen M, Tervonen A, Honkanen S. Angled sidewalls in silicon slot waveguides: conformal filling and mode properties. OPTICS EXPRESS 2009; 17:21066-21076. [PMID: 19997345 DOI: 10.1364/oe.17.021066] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Effect of angled sidewalls on the filling and properties of silicon slot waveguides is discussed. We demonstrate complete filling of slot waveguide structures with oxide material systems using the atomic layer deposition technique and discuss use of various slot filling materials. Properties of the optical modes in angled-sidewall slot waveguides are studied. Enhanced vertical confinement is obtained with certain waveguide parameters. The reduced effective mode area enhances e.g. nonlinear effects in the waveguide. We discuss the use of atomic layer deposition in realization of filled slot waveguides optimized for all-optical functionalities.
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Affiliation(s)
- A Säynätjoki
- Department of Micro and Nanosciences, Helsinki University of Technology (TKK), Micronova, Tietotie 3, FIN-02015 Espoo, Finland.
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16
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Gondarenko A, Lipson M. Low modal volume dipole-like dielectric slab resonator. OPTICS EXPRESS 2008; 16:17689-17694. [PMID: 18958049 DOI: 10.1364/oe.16.017689] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We propose a novel geometry in a silicon planar resonator with an ultra-small modal volume of 0.01(lambda/2n)(3). The geometry induces strong electric field discontinuities to decrease the modal volume of the cavity below 1(lambda/2n)(3) The proposed structure and other common resonators such as 1D and 2D photonic crystal resonators are compared for tradeoffs in confinement and quality factors.
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Affiliation(s)
- Alexander Gondarenko
- Department of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA.
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17
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Development and Uses of Artificial Intelligence in Chemistry. REVIEWS IN COMPUTATIONAL CHEMISTRY 2007. [DOI: 10.1002/9780470189078.ch8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/10/2023]
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