1
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Baiocco D, Lopez-Quintas I, Vázquez de Aldana JR, Tonelli M, Tredicucci A. High efficiency diode-pumped Pr:LiLuF 4 visible lasers in femtosecond-laser-written waveguides. Opt Express 2024; 32:9767-9776. [PMID: 38571202 DOI: 10.1364/oe.516789] [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: 12/21/2023] [Accepted: 01/29/2024] [Indexed: 04/05/2024]
Abstract
In this work we investigate the power scaling of diode-pumped Pr:LiLuF4 waveguide lasers produced by direct femtosecond writing. The waveguides studied consisted in depressed cladding waveguides with different geometries. We observed laser emission at 604 nm, achieving a maximum output power of 275 mW and a slope efficiency of 40%, and 721 nm, demonstrating 310 mW of output power and a slope efficiency of 50%. Moreover, we obtained, what we believe is for the first time in a diode-pumped waveguide, laser emission at 523 nm, with a maximum output power of 65 mW and a slope efficiency of 11%. In the end, we also demonstrated the first diode-pumped operation of a single-transverse-mode waveguide laser at 721 nm, reaching a maximum output power of 28 mW and maintaining a high quality beam with an M2 of 1.1.
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2
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Gennari F, Pagano M, Toncelli A, Lisanti MT, Paoletti R, Roversi PF, Tredicucci A, Giaccone M. Terahertz imaging for non-invasive classification of healthy and cimiciato-infected hazelnuts. Heliyon 2023; 9:e19891. [PMID: 37809509 PMCID: PMC10559270 DOI: 10.1016/j.heliyon.2023.e19891] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 10/10/2023] Open
Abstract
The development of new non-invasive approaches able to recognize defective food is currently a lively field of research. In particular, a simple and non-destructive method able to recognize defective hazelnuts, such as cimiciato-infected ones, in real-time is still missing. This study has been designed to detect the presence of such damaged hazelnuts. To this aim, a measurement setup based on terahertz (THz) radiation has been developed. Images of a sample of 150 hazelnuts have been acquired in the low THz range by a compact and portable active imaging system equipped with a 0.14 THz source and identified as Healthy Hazelnuts (HH) or Cimiciato Hazelnut (CH) after visual inspection. All images have been analyzed to find the average transmission of the THz radiation within the sample area. The differences in the distribution of the two populations have been used to set up a classification scheme aimed at the discrimination between healthy and injured samples. The performance of the classification scheme has been assessed through the use of the confusion matrix on 50 samples. The False Positive Rate (FPR) and True Negative Rate (TNR) are 0% and 100%, respectively. On the other hand, the True Positive Rate (TPR) and False Negative Rate (FNR) are 75% and 25%, respectively. These results are relevant from the perspective of the development of a simple, automatic, real-time method for the discrimination of cimiciato-infected hazelnuts in the processing industry.
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Affiliation(s)
- Fulvia Gennari
- Dipartimento di Fisica “E. Fermi”, Università di Pisa, Largo B. Pontecorvo 3, 56127, Pisa, Italy
| | - Mario Pagano
- Institute of Research on Terrestrial Ecosystems (IRET), National Research Council (CNR), Via Madonna del Piano 10, 50019, Sesto Fiorentino, Italy
| | - Alessandra Toncelli
- Dipartimento di Fisica “E. Fermi”, Università di Pisa, Largo B. Pontecorvo 3, 56127, Pisa, Italy
- Centro per l’Integrazione della Strumentazione dell’Università di Pisa (CISUP), Lungarno Pacinotti 43/44, 56126, Pisa, Italy
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Largo B. Pontecorvo 3, 56127, Pisa, Italy
- Istituto Nanoscienze – CNR, Piazza S. Silvestro 12, 56127, Pisa, Italy
| | - Maria Tiziana Lisanti
- Università degli Studi di Napoli Federico II, Dipartimento di Agraria, Sezione di Scienze della Vigna e del Vino, viale Italia 60, 83100, Avellino, Italy
| | - Riccardo Paoletti
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Largo B. Pontecorvo 3, 56127, Pisa, Italy
- Dipartimento di Scienze Fisiche, della Terra e dell’Ambiente, Sezione di Fisica, Università di Siena, via Roma 56, 53100, Siena, Italy
| | - Pio Federico Roversi
- CREA, Research Centre for Plant Protection and Certification, 50125, Firenze, Italy
| | - Alessandro Tredicucci
- Dipartimento di Fisica “E. Fermi”, Università di Pisa, Largo B. Pontecorvo 3, 56127, Pisa, Italy
- Centro per l’Integrazione della Strumentazione dell’Università di Pisa (CISUP), Lungarno Pacinotti 43/44, 56126, Pisa, Italy
- Istituto Nanoscienze – CNR, Piazza S. Silvestro 12, 56127, Pisa, Italy
| | - Matteo Giaccone
- Institute for Mediterranean Agricultural and Forestry Systems, National Research Council, 80055 P.le Enrico, Fermi 1 - Loc. Porto del Granatello, 80055, Portici, Naples, Italy
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3
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Baiocco D, Lopez-Quintas I, Vázquez de Aldana JR, Tonelli M, Tredicucci A. Diode-pumped visible lasing in femtosecond-laser-written Pr:LiLuF 4 waveguide. Opt Lett 2023; 48:1734-1737. [PMID: 37221753 DOI: 10.1364/ol.487318] [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: 02/07/2023] [Accepted: 03/08/2023] [Indexed: 05/25/2023]
Abstract
In this Letter we report the realization of a femtosecond-laser-written diode-pumped Pr:LiLuF4 visible waveguide laser. The waveguide studied in this work consisted of a depressed-index cladding, whose design and fabrication were optimized to minimize the propagation loss. Laser emission has been achieved at 604 nm and 721 nm, with output power of 86 mW and 60 mW, respectively, and slope efficiencies of 16% and 14%. In addition, we obtained, for the first time in a praseodymium-based waveguide laser, stable continuous-wave laser operation at 698 nm (3 mW of output power and 0.46% of slope efficiency), corresponding to the wavelength necessary for the clock transition of the strontium-based atomic clock. The waveguide laser emission at this wavelength is mainly in the fundamental mode (i.e., the larger propagation constant mode) showing a nearly Gaussian intensity profile.
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4
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Zanotto S, Bonatti L, Pantano MF, Mišeikis V, Speranza G, Giovannini T, Coletti C, Cappelli C, Tredicucci A, Toncelli A. Strain-Induced Plasmon Confinement in Polycrystalline Graphene. ACS Photonics 2023; 10:394-400. [PMID: 36820323 PMCID: PMC9936574 DOI: 10.1021/acsphotonics.2c01157] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Indexed: 06/18/2023]
Abstract
Terahertz spectroscopy is a perfect tool to investigate the electronic intraband conductivity of graphene, but a phenomenological model (Drude-Smith) is often needed to describe disorder. By studying the THz response of isotropically strained polycrystalline graphene and using a fully atomistic computational approach to fit the results, we demonstrate here the connection between the Drude-Smith parameters and the microscopic behavior. Importantly, we clearly show that the strain-induced changes in the conductivity originate mainly from the increased separation between the single-crystal grains, leading to enchanced localization of the plasmon excitations. Only at the lowest strain values explored, a behavior consistent with the deformation of the individual grains can instead be observed.
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Affiliation(s)
- Simone Zanotto
- NEST, Istituto Nanoscienze − CNR and Scuola Normale
Superiore, Piazza S. Silvestro 12, Pisa, 56127, Italy
| | - Luca Bonatti
- Scuola
Normale Superiore, Piazza dei Cavalieri 7, Pisa, 56126, Italy
| | - Maria F. Pantano
- Department
of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, Trento, 38123, Italy
| | - Vaidotas Mišeikis
- Center
for Nanotechnology Innovation @NEST - Istituto Italiano di Tecnologia, Piazza S. Silvestro 12, Pisa, 56127, Italy
| | - Giorgio Speranza
- Centre
for Materials and Microsystems, Fondazione
Bruno Kessler, via Sommarive 18, Trento, I-38123, Italy
| | | | - Camilla Coletti
- Center
for Nanotechnology Innovation @NEST - Istituto Italiano di Tecnologia, Piazza S. Silvestro 12, Pisa, 56127, Italy
| | - Chiara Cappelli
- Scuola
Normale Superiore, Piazza dei Cavalieri 7, Pisa, 56126, Italy
| | - Alessandro Tredicucci
- Dipartimento
di Fisica ”E. Fermi” and CISUP, Università di Pisa, and Istituto Nanoscienze - CNR, Largo Pontecorvo 3, Pisa, 56127, Italy
| | - Alessandra Toncelli
- Dipartimento
di Fisica ”E. Fermi” and CISUP, Università di Pisa, and Istituto Nanoscienze - CNR, Largo Pontecorvo 3, Pisa, 56127, Italy
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5
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Melchioni N, Fabbri F, Tredicucci A, Bianco F. Periodic Structural Defects in Graphene Sheets Engineered via Electron Irradiation. Micromachines (Basel) 2022; 13:1666. [PMID: 36296019 PMCID: PMC9606931 DOI: 10.3390/mi13101666] [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: 09/05/2022] [Revised: 09/23/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Artificially-induced defects in the lattice of graphene are a powerful tool for engineering the properties of the crystal, especially if organized in highly-ordered structures such as periodic arrays. A method to deterministically induce defects in graphene is to irradiate the crystal with low-energy (<20 keV) electrons delivered by a scanning electron microscope. However, the nanometric precision granted by the focused beam can be hindered by the pattern irradiation itself due to the small lateral separation among the elements, which can prevent the generation of sharp features. An accurate analysis of the achievable resolution is thus essential for practical applications. To this end, we investigated patterns generated by low-energy electron irradiation combining atomic force microscopy and micro-Raman spectroscopy measurements. We proved that it is possible to create well-defined periodic patterns with precision of a few tens of nanometers. We found that the defected lines are influenced by electrons back-scattered by the substrate, which limit the achievable resolution. We provided a model that takes into account such substrate effects. The findings of our study allow the design and easily accessible fabrication of graphene devices featuring complex defect engineering, with a remarkable impact on technologies exploiting the increased surface reactivity.
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Affiliation(s)
- Nicola Melchioni
- NEST Laboratory, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy
| | - Filippo Fabbri
- NEST Laboratory, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy
| | - Alessandro Tredicucci
- Istituto Nanoscienze-CNR, Piazza San Silvestro 12, I-56127 Pisa, Italy
- Dipartimento di Fisica “E. Fermi”, Università di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy
| | - Federica Bianco
- NEST Laboratory, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy
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6
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Abstract
Fast room-temperature imaging at terahertz (THz) and subterahertz (sub-THz) frequencies is an interesting technique that could unleash the full potential of plenty of applications in security, healthcare, and industrial production. In this Letter, we introduce micromechanical bolometers based on silicon nitride trampoline membranes as broad-range detectors down to sub-THz frequencies. They show, at the longest wavelengths, room-temperature noise-equivalent powers comparable to those of state-of-the-art commercial devices (∼100 pW Hz-1/2), which, along with the good operation speed and the easy, large-scale fabrication process, could make the trampoline membrane the next candidate for cheap room-temperature THz imaging and related applications.
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Affiliation(s)
- Leonardo Vicarelli
- Laboratorio
NEST, Scuola Normale Superiore and Istituto
Nanoscienze - CNR, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Alessandro Tredicucci
- Laboratorio
NEST, Scuola Normale Superiore and Istituto
Nanoscienze - CNR, Piazza San Silvestro 12, 56127 Pisa, Italy
- Dipartimento
di Fisica, Università di Pisa, Largo B. Pontecorvo 3, 56127 Pisa, Italy
| | - Alessandro Pitanti
- Laboratorio
NEST, Scuola Normale Superiore and Istituto
Nanoscienze - CNR, Piazza San Silvestro 12, 56127 Pisa, Italy
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7
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Ciampalini G, Fabbri F, Menichetti G, Buoni L, Pace S, Mišeikis V, Pitanti A, Pisignano D, Coletti C, Tredicucci A, Roddaro S. Unexpected Electron Transport Suppression in a Heterostructured Graphene-MoS 2 Multiple Field-Effect Transistor Architecture. ACS Nano 2022; 16:1291-1300. [PMID: 34939407 PMCID: PMC8793137 DOI: 10.1021/acsnano.1c09131] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
We demonstrate a graphene-MoS2 architecture integrating multiple field-effect transistors (FETs), and we independently probe and correlate the conducting properties of van der Waals coupled graphene-MoS2 contacts with those of the MoS2 channels. Devices are fabricated starting from high-quality single-crystal monolayers grown by chemical vapor deposition. The heterojunction was investigated by scanning Raman and photoluminescence spectroscopies. Moreover, transconductance curves of MoS2 are compared with the current-voltage characteristics of graphene contact stripes, revealing a significant suppression of transport on the n-side of the transconductance curve. On the basis of ab initio modeling, the effect is understood in terms of trapping by sulfur vacancies, which counterintuitively depends on the field effect, even though the graphene contact layer is positioned between the backgate and the MoS2 channel.
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Affiliation(s)
- Gaia Ciampalini
- Dipartimento
di Fisica “E. Fermi”, Università
di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
- Graphene
Labs, Istituto Italiano di Tecnologia, Via Morego 30, I-16 163 Genova, Italy
- NEST,
CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, I-56 127 Pisa, Italy
| | - Filippo Fabbri
- NEST,
CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, I-56 127 Pisa, Italy
| | - Guido Menichetti
- Dipartimento
di Fisica “E. Fermi”, Università
di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
- Graphene
Labs, Istituto Italiano di Tecnologia, Via Morego 30, I-16 163 Genova, Italy
| | - Luca Buoni
- Dipartimento
di Fisica “E. Fermi”, Università
di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - Simona Pace
- Graphene
Labs, Istituto Italiano di Tecnologia, Via Morego 30, I-16 163 Genova, Italy
- Center
for Nanotechnology Innovation @NEST, Istituto
Italiano di Tecnologia, Piazza San Silvestro 12, I-56 127 Pisa, Italy
| | - Vaidotas Mišeikis
- Graphene
Labs, Istituto Italiano di Tecnologia, Via Morego 30, I-16 163 Genova, Italy
- Center
for Nanotechnology Innovation @NEST, Istituto
Italiano di Tecnologia, Piazza San Silvestro 12, I-56 127 Pisa, Italy
| | - Alessandro Pitanti
- NEST,
CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, I-56 127 Pisa, Italy
| | - Dario Pisignano
- Dipartimento
di Fisica “E. Fermi”, Università
di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
- NEST,
CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, I-56 127 Pisa, Italy
| | - Camilla Coletti
- Graphene
Labs, Istituto Italiano di Tecnologia, Via Morego 30, I-16 163 Genova, Italy
- Center
for Nanotechnology Innovation @NEST, Istituto
Italiano di Tecnologia, Piazza San Silvestro 12, I-56 127 Pisa, Italy
| | - Alessandro Tredicucci
- Dipartimento
di Fisica “E. Fermi”, Università
di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
- NEST,
CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, I-56 127 Pisa, Italy
| | - Stefano Roddaro
- Dipartimento
di Fisica “E. Fermi”, Università
di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
- NEST,
CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, I-56 127 Pisa, Italy
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8
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Ottomaniello A, Conte G, Pitanti A, Vicarelli L, Profeti A, Beere HE, Ritchie DA, Mattoli V, Bianco F, Tredicucci A. Continuous wave vertical emission from terahertz microcavity lasers with a dual injection scheme. Opt Express 2021; 29:33602-33614. [PMID: 34809170 DOI: 10.1364/oe.430742] [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: 05/24/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
Quantum cascade lasers (QCLs) represent a most promising compact source at terahertz (THz) frequencies, but efficiency of their continuous wave (CW) operation still needs to be improved to achieve large-scale exploitation. Here, we demonstrate highly efficient operation of a subwavelength microcavity laser consisting of two evanescently coupled whispering gallery microdisk resonators. Exploiting a dual injection scheme for the laser cavity, single mode CW vertical emission at 3.3 THz is obtained at 10 K with 6.4 mA threshold current and 145 mW/A slope efficiency up to 320 μW emitted power measured in quasi-CW mode. The tuning of the laser emission directionality is also obtained by independently varying the pumping strength between the microdisks. By connecting the resonators through a suspended gold bridge, the laser out-coupling efficiency in the vertical direction is strongly enhanced. Owing to the high brightness, low-power consumption and CW operation, the proposed microcavity laser design could allow the realization of high-performance CW THz QCLs ready for massive parallelization.
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9
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Ottomaniello A, Keeley J, Rubino P, Li L, Cecchini M, Linfield EH, Davies AG, Dean P, Pitanti A, Tredicucci A. Optomechanical response with nanometer resolution in the self-mixing signal of a terahertz quantum cascade laser. Opt Lett 2019; 44:5663-5666. [PMID: 31774748 DOI: 10.1364/ol.44.005663] [Citation(s) in RCA: 1] [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: 05/15/2023]
Abstract
Owing to their intrinsic stability against optical feedback (OF), quantum cascade lasers (QCLs) represent a uniquely versatile source to further improve self-mixing interferometry at mid-infrared and terahertz (THz) frequencies. Here, we show the feasibility of detecting with nanometer precision, the deeply subwavelength ($ \lt \lambda /6000 $<λ/6000) mechanical vibrations of a suspended $ {{\rm Si}_3}{{\rm N}_4} $Si3N4 membrane used as the external element of a THz QCL feedback interferometer. Besides representing an extension of the applicability of vibrometric characterization at THz frequencies, our system can be exploited for the realization of optomechanical applications, such as dynamical switching between different OF regimes and a still-lacking THz master-slave configuration.
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10
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Pagano M, Baldacci L, Ottomaniello A, de Dato G, Chianucci F, Masini L, Carelli G, Toncelli A, Storchi P, Tredicucci A, Corona P. THz Water Transmittance and Leaf Surface Area: An Effective Nondestructive Method for Determining Leaf Water Content. Sensors (Basel) 2019; 19:E4838. [PMID: 31698861 PMCID: PMC6891343 DOI: 10.3390/s19224838] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 10/27/2019] [Accepted: 10/29/2019] [Indexed: 02/07/2023]
Abstract
Water availability is a major limiting factor in plant productivity and plays a key role in plant species distribution over a given area. New technologies, such as terahertz quantum cascade lasers (THz-QCLs) have proven to be non-invasive, effective, and accurate tools for measuring and monitoring leaf water content. This study explores the feasibility of using an advanced THz-QCL device for measuring the absolute leaf water content in Corylus avellana L., Laurus nobilis L., Ostrya carpinifolia Scop., Quercus ilex L., Quercus suber L., and Vitis vinifera L. (cv. Sangiovese). A recently proposed, simple spectroscopic technique was used, consisting in determining the transmission of the THz light beam through the leaf combined with a photographic measurement of the leaf area. A significant correlation was found between the product of the leaf optical depth (τ) and the leaf surface area (LA) with the leaf water mass (Mw) for all the studied species (Pearson's r test, p ≤ 0.05). In all cases, the best fit regression line, in the graphs of τLA as a function of Mw, displayed R2 values always greater than 0.85. The method proposed can be combined with water stress indices of plants in order to gain a better understanding of the leaf water management processes or to indirectly monitor the kinetics of leaf invasion by pathogenic bacteria, possibly leading to the development of specific models to study and fight them.
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Affiliation(s)
- Mario Pagano
- CREA—Research Centre for Plant Protection and Certification, Via di Lanciola 12/A, 50125 Firenze, Italy
- CREA—Research Centre for Viticulture and Enology, Viale Santa Margherita 80, 52100 Arezzo, Italy;
| | - Lorenzo Baldacci
- NEST, CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56124 Pisa, Italy; (L.B.); (A.O.); (L.M.); (A.T.)
| | - Andrea Ottomaniello
- NEST, CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56124 Pisa, Italy; (L.B.); (A.O.); (L.M.); (A.T.)
- Dipartimento di Fisica “E. Fermi”, Università di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy; (G.C.); (A.T.)
| | - Giovanbattista de Dato
- CREA—Research Centre for Forestry and Wood, Viale Santa Margherita 80, 52100 Arezzo, Italy; (G.d.D.); (F.C.); (P.C.)
| | - Francesco Chianucci
- CREA—Research Centre for Forestry and Wood, Viale Santa Margherita 80, 52100 Arezzo, Italy; (G.d.D.); (F.C.); (P.C.)
| | - Luca Masini
- NEST, CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56124 Pisa, Italy; (L.B.); (A.O.); (L.M.); (A.T.)
| | - Giorgio Carelli
- Dipartimento di Fisica “E. Fermi”, Università di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy; (G.C.); (A.T.)
| | - Alessandra Toncelli
- Dipartimento di Fisica “E. Fermi”, Università di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy; (G.C.); (A.T.)
| | - Paolo Storchi
- CREA—Research Centre for Viticulture and Enology, Viale Santa Margherita 80, 52100 Arezzo, Italy;
| | - Alessandro Tredicucci
- NEST, CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56124 Pisa, Italy; (L.B.); (A.O.); (L.M.); (A.T.)
- Dipartimento di Fisica “E. Fermi”, Università di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy; (G.C.); (A.T.)
| | - Piermaria Corona
- CREA—Research Centre for Forestry and Wood, Viale Santa Margherita 80, 52100 Arezzo, Italy; (G.d.D.); (F.C.); (P.C.)
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11
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Guglielmero L, Guazzelli L, Toncelli A, Chiappe C, Tredicucci A, Pomelli CS. An insight into the intermolecular vibrational modes of dicationic ionic liquids through far-infrared spectroscopy and DFT calculations. RSC Adv 2019; 9:30269-30276. [PMID: 35530250 PMCID: PMC9072084 DOI: 10.1039/c9ra05735h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 09/18/2019] [Indexed: 12/03/2022] Open
Abstract
Dicationic ionic liquids (DILs) are a subclass of the ionic liquid (IL) family and are characterized by two cationic head groups linked by means of a spacer. While DILs are increasingly attracting interest due to their peculiar physico-chemical properties, there is still a lack of understanding of their intermolecular interactions. Herein, we report our investigations on the intermolecular vibrational modes of two bromide DILs and of a bistriflimide DIL. The minimal possible neutral cluster of ions was studied as a simplified model of these systems and was optimized at the DFT level. Normal modes of two sandwich-like conformers were then calculated using the harmonic approximation with analytical computation of the second derivatives of molecular energy with respect to the atomic coordinates. The calculated spectra were compared to far-infrared experimental spectra and two groups of peaks over three, for the two bromide DILs, and three over five, for the Tf2N− DIL, were described by the proposed neutral cluster model. Therefore, this model represents a reliable and computationally affordable model for the exploration of the intermolecular interactions of this kind of system. The minimal cluster of ions represents a reliable and computationally affordable model for the exploration of the intermolecular interactions of dicationic ionic liquids.![]()
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Affiliation(s)
| | | | - Alessandra Toncelli
- Dipartimento di Fisica “E. Fermi” and Istituto Nanoscienze CNR
- Università di Pisa
- 56127 Pisa
- Italy
| | | | - Alessandro Tredicucci
- Dipartimento di Fisica “E. Fermi” and Istituto Nanoscienze CNR
- Università di Pisa
- 56127 Pisa
- Italy
- Laboratorio NEST
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12
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Rossi A, Spirito D, Bianco F, Forti S, Fabbri F, Büch H, Tredicucci A, Krahne R, Coletti C. Patterned tungsten disulfide/graphene heterostructures for efficient multifunctional optoelectronic devices. Nanoscale 2018; 10:4332-4338. [PMID: 29443347 DOI: 10.1039/c7nr08703a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
One of the major issues in graphene-based optoelectronics is to scale-up high-performing devices. In this work, we report an original approach for the fabrication of efficient optoelectronic devices from scalable tungsten disulfide (WS2)/graphene heterostructures. Our approach allows for the patterned growth of WS2 on graphene and facilitates the realization of ohmic contacts. Photodetectors fabricated with WS2 on epitaxial graphene on silicon carbide (SiC) present, when illuminated with red light, a maximum responsivity R ∼220 A W-1, a detectivity D* ∼2.0 × 109 Jones and a -3 dB bandwidth of 250 Hz. The retrieved detectivity is 3 orders of magnitude higher than that obtained with graphene-only devices at the same wavelength. For shorter illumination wavelengths we observe a persistent photocurrent with a nearly complete charge retention, which originates from deep trap levels in the SiC substrate. This work ultimately demonstrates that WS2/graphene optoelectronic devices with promising performances can be obtained in a scalable manner. Furthermore, by combining wavelength-selective memory, enhanced responsivity and fast detection, this system is of interest for the implementation of 2d-based data storage devices.
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Affiliation(s)
- A Rossi
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza S. Silvestro 12, 56127 Pisa, Italy. and NEST, Istituto Nanoscienze - CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - D Spirito
- Nanochemistry Department, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - F Bianco
- NEST, Istituto Nanoscienze - CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - S Forti
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza S. Silvestro 12, 56127 Pisa, Italy.
| | - F Fabbri
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza S. Silvestro 12, 56127 Pisa, Italy.
| | - H Büch
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza S. Silvestro 12, 56127 Pisa, Italy.
| | - A Tredicucci
- NEST, Istituto Nanoscienze - CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy and Dipartimento di Fisica "E. Fermi", Università di Pisa, L.go Pontecorvo 3, 56127 Pisa, Italy
| | - R Krahne
- Nanochemistry Department, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy and Graphene Labs, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - C Coletti
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza S. Silvestro 12, 56127 Pisa, Italy. and Graphene Labs, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
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13
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Zanotto S, La Rocca GC, Tredicucci A. Understanding and overcoming fundamental limits of asymmetric light-light switches. Opt Express 2018; 26:3618-3626. [PMID: 29401889 DOI: 10.1364/oe.26.003618] [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: 11/02/2017] [Accepted: 12/04/2017] [Indexed: 06/07/2023]
Abstract
The interplay between interference and absorption leads to interesting phenomena like coherent perfect absorption and coherent perfect transparency (CPA and CPT), which can be exploited for fully optical modulation. While it is known that it is possible to harness CPA and CPT for switching a strong signal beam with a weak control beam, it is not immediate that this process suffers from a fundamental compromise between the device efficiency (quantified by device loss and modulation depth) and the asymmetry between signal and control intensity desired for operation. This article quantifies this compromise and outlines a possible way to overcome it by means of a combination of optical gain and loss in the same photonic component. A general formulation and a specific device realization are both discussed.
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14
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Ottomaniello A, Zanotto S, Baldacci L, Pitanti A, Bianco F, Tredicucci A. Symmetry enhanced non-reciprocal polarization rotation in a terahertz metal-graphene metasurface. Opt Express 2018; 26:3328-3340. [PMID: 29401862 DOI: 10.1364/oe.26.003328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 11/21/2017] [Indexed: 06/07/2023]
Abstract
In the present article we numerically investigated the magneto-optical behaviour of a sub-wavelength structure composed by a monolayer graphene and a metallic metasurface of optical resonators. Using this hybrid graphene-metal structure, a large increase of the non-reciprocal polarization rotation of graphene can be achieved over a broad range of terahertz frequencies. We demonstrate that the symmetry of the resonator geometry plays a key role for the performance of the system: in particular, increasing the symmetry of the resonator the non-reciprocal properties can be progressively enhanced. Moreover, the possibility to exploit the metallic metasurface as a voltage gate to vary the graphene Fermi energy allows the system working point to be tuned to the desired frequency range. Another peculiar result is the achievement of a structure able to operate both in transmission and reflection with almost the same performance, but in a different frequency range of operation. The described system is hence a sub-wavelength, tunable, multifunctional, effective non-reciprocal element in the terahertz region.
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15
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Masini L, Pitanti A, Baldacci L, Vitiello MS, Degl'Innocenti R, Beere HE, Ritchie DA, Tredicucci A. Continuous-wave laser operation of a dipole antenna terahertz microresonator. Light Sci Appl 2017; 6:e17054. [PMID: 30167200 PMCID: PMC6061901 DOI: 10.1038/lsa.2017.54] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 03/24/2017] [Accepted: 03/26/2017] [Indexed: 05/30/2023]
Abstract
Resonators and the way they couple to external radiation rely on very different concepts if one considers devices belonging to the photonic and electronic worlds. The terahertz frequency range, however, provides intriguing possibilities for the development of hybrid technologies that merge ideas from both fields in novel functional designs. In this paper, we show that high-quality, subwavelength, whispering-gallery lasers can be combined to form a linear dipole antenna, which creates a very efficient, low-threshold laser emission in a collimated beam pattern. For this purpose, we employ a terahertz quantum-cascade active region patterned into two 19-μm-radius microdisks coupled by a suspended metallic bridge, which simultaneously acts as an inductive antenna and produces the dipole symmetry of the lasing mode. Continuous-wave vertical emission is demonstrated at approximately 3.5 THz in a very regular, low-divergence (±10°) beam, with a high slope efficiency of at least 160 mW A-1 and a mere 6 mA of threshold current, which is ensured by the ultra-small resonator size (VRES/λ3≈10-2). The extremely low power consumption and the superior beam brightness make this concept very promising for the development of miniaturized and portable THz sources to be used in the field for imaging and sensing applications as well as for exploring novel optomechanical intracavity effects.
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Affiliation(s)
- Luca Masini
- NEST, CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Alessandro Pitanti
- NEST, CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Lorenzo Baldacci
- NEST, CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Miriam S Vitiello
- NEST, CNR—Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
| | | | - Harvey E Beere
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
| | - David A Ritchie
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
| | - Alessandro Tredicucci
- NEST, CNR—Istituto Nanoscienze and Dipartimento di Fisica ‘E. Fermi’, Università degli studi di Pisa, 56127 Pisa, Italy
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16
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Baldacci L, Pagano M, Masini L, Toncelli A, Carelli G, Storchi P, Tredicucci A. Non-invasive absolute measurement of leaf water content using terahertz quantum cascade lasers. Plant Methods 2017; 13:51. [PMID: 28638439 PMCID: PMC5474302 DOI: 10.1186/s13007-017-0197-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
BACKGROUND Plant water resource management is one of the main future challenges to fight recent climatic changes. The knowledge of the plant water content could be indispensable for water saving strategies. Terahertz spectroscopic techniques are particularly promising as a non-invasive tool for measuring leaf water content, thanks to the high predominance of the water contribution to the total leaf absorption. Terahertz quantum cascade lasers (THz QCL) are one of the most successful sources of THz radiation. RESULTS Here we present a new method which improves the precision of THz techniques by combining a transmission measurement performed using a THz QCL source, with simple pictures of leaves taken by an optical camera. As a proof of principle, we performed transmission measurements on six plants of Vitis vinifera L. (cv "Colorino"). We found a linear law which relates the leaf water mass to the product between the leaf optical depth in the THz and the projected area. Results are in optimal agreement with the proposed law, which reproduces the experimental data with 95% accuracy. CONCLUSIONS This method may overcome the issues related to intra-variety heterogeneities and retrieve the leaf water mass in a fast, simple, and non-invasive way. In the future this technique could highlight different behaviours in preserving the water status during drought stress.
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Affiliation(s)
- Lorenzo Baldacci
- NEST, CNR Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Mario Pagano
- Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria, Centro di ricerca per la Viticoltura e l’Enologia, Viale Santa Margherita 80, 52100 Arezzo, Italy
| | - Luca Masini
- NEST, CNR Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Alessandra Toncelli
- NEST, CNR Istituto Nanoscienze and Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy
| | - Giorgio Carelli
- Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy
| | - Paolo Storchi
- Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria, Centro di ricerca per la Viticoltura e l’Enologia, Viale Santa Margherita 80, 52100 Arezzo, Italy
| | - Alessandro Tredicucci
- NEST, CNR Istituto Nanoscienze and Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy
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17
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Arcangeli A, Rossella F, Tomadin A, Xu J, Ercolani D, Sorba L, Beltram F, Tredicucci A, Polini M, Roddaro S. Gate-Tunable Spatial Modulation of Localized Plasmon Resonances. Nano Lett 2016; 16:5688-5693. [PMID: 27479039 DOI: 10.1021/acs.nanolett.6b02351] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We demonstrate localization and field-effect spatial control of the plasmon resonance in semiconductor nanostructures, using scattering-type scanning near-field optical microscopy in the mid-infrared region. We adopt InAs nanowires embedding a graded doping profile to modulate the free carrier density along the axial direction. Our near-field measurements have a spatial resolution of 20 nm and demonstrate the presence of a local resonant feature whose position can be controlled by a back-gate bias voltage. In the present implementation, field-effect induces a modulation of the free carrier density profile yielding a spatial shift of the plasmon resonance of the order of 100 nm. We discuss the relevance of our electrically tunable nanoplasmonic architectures in view of innovative optoelectronic devices concepts.
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Affiliation(s)
- Andrea Arcangeli
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza san Silvestro 12, I-56127 Pisa, Italy
| | - Francesco Rossella
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza san Silvestro 12, I-56127 Pisa, Italy
| | - Andrea Tomadin
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza san Silvestro 12, I-56127 Pisa, Italy
| | - Jihua Xu
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza san Silvestro 12, I-56127 Pisa, Italy
| | - Daniele Ercolani
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza san Silvestro 12, I-56127 Pisa, Italy
| | - Lucia Sorba
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza san Silvestro 12, I-56127 Pisa, Italy
| | - Fabio Beltram
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza san Silvestro 12, I-56127 Pisa, Italy
| | - Alessandro Tredicucci
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza san Silvestro 12, I-56127 Pisa, Italy
- Dipartimento di Fisica, Università di Pisa , Largo Pontecorvo 3, I-56127 Pisa, Italy
| | - Marco Polini
- Istituto Italiano di Tecnologia, Graphene Laboratories , Via Morego 30, I-16163 Genova, Italy
- NEST, Scuola Normale Superiore , Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - Stefano Roddaro
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , Piazza san Silvestro 12, I-56127 Pisa, Italy
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18
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Baldacci L, Pitanti A, Masini L, Arcangeli A, Colangelo F, Navarro-Urrios D, Tredicucci A. Thermal noise and optomechanical features in the emission of a membrane-coupled compound cavity laser diode. Sci Rep 2016; 6:31489. [PMID: 27538586 PMCID: PMC4990904 DOI: 10.1038/srep31489] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [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: 03/04/2016] [Accepted: 07/19/2016] [Indexed: 11/10/2022] Open
Abstract
We demonstrate the use of a compound optical cavity as linear displacement detector, by measuring the thermal motion of a silicon nitride suspended membrane acting as the external mirror of a near-infrared Littrow laser diode. Fluctuations in the laser optical power induced by the membrane vibrations are collected by a photodiode integrated within the laser, and then measured with a spectrum analyzer. The dynamics of the membrane driven by a piezoelectric actuator is investigated as a function of air pressure and actuator displacement in a homodyne configuration. The high Q-factor (~3.4 · 10(4) at 8.3 · 10(-3) mbar) of the fundamental mechanical mode at ~73 kHz guarantees a detection sensitivity high enough for direct measurement of thermal motion at room temperature (~87 pm RMS). The compound cavity system here introduced can be employed as a table-top, cost-effective linear displacement detector for cavity optomechanics. Furthermore, thanks to the strong optical nonlinearities of the laser compound cavity, these systems open new perspectives in the study of non-Markovian quantum properties at the mesoscale.
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Affiliation(s)
- Lorenzo Baldacci
- NEST, CNR Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56127, Pisa, (Italy)
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà 33, 56127, Pisa, (Italy)
| | - Alessandro Pitanti
- NEST, CNR Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56127, Pisa, (Italy)
| | - Luca Masini
- NEST, CNR Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56127, Pisa, (Italy)
| | - Andrea Arcangeli
- NEST, CNR Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56127, Pisa, (Italy)
| | - Francesco Colangelo
- NEST, CNR Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56127, Pisa, (Italy)
| | - Daniel Navarro-Urrios
- NEST, CNR Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56127, Pisa, (Italy)
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIS and the Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193, Barcelona, (Spain)
| | - Alessandro Tredicucci
- NEST, CNR Istituto Nanoscienze and Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, 56127, Pisa, (Italy)
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19
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Meng F, Thomson MD, Bianco F, Rossi A, Convertino D, Tredicucci A, Coletti C, Roskos HG. Saturable absorption of femtosecond optical pulses in multilayer turbostratic graphene. Opt Express 2016; 24:15261-15273. [PMID: 27410803 DOI: 10.1364/oe.24.015261] [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: 06/06/2023]
Abstract
We investigate the nonlinear transmission of a ~280-layer turbostratic graphene sheet for near-infrared amplifier laser pulses (775 nm, Ti:sapphire laser) with a duration of 150-fs and 20-fs. Saturable absorption is observed in both cases, however it is not very strong, amounting to ~13% transmittance change for the 20-fs (150-fs) pulses at a peak intensity of 30 GW/cm2 (4 GW/cm2). The dependence on incident peak intensity is reproduced well using a theoretical model for the time-dependent saturable absorption, where the excited carriers vacate the photo-excited energy range within 3-5 fs, which we attribute to energy redistribution due to carrier-carrier scattering. This is also supported by spectrally resolved measurements for the 20-fs pulses, which show a marked dependence of the degree of saturation on the photon energy. A key result is that the shorter pulses do not yield a lower saturation fluence, due to the combined effects of the broader excitation bandwidth, and the rapid and broad energy redistribution. We also predict the potential performance of multilayer graphene samples for removing pedestal and pre-pulse structure from ultrafast high-energy pulses.
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20
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Zanotto S, Tredicucci A. Erratum: Corrigendum: Universal lineshapes at the crossover between weak and strong critical coupling in Fano-resonant coupled oscillators. Sci Rep 2016; 6:27046. [PMID: 27253609 PMCID: PMC4890554 DOI: 10.1038/srep27046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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21
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Zanotto S, Tredicucci A. Universal lineshapes at the crossover between weak and strong critical coupling in Fano-resonant coupled oscillators. Sci Rep 2016; 6:24592. [PMID: 27091489 PMCID: PMC4836300 DOI: 10.1038/srep24592] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 03/30/2016] [Indexed: 11/09/2022] Open
Abstract
In this article we discuss a model describing key features concerning the lineshapes and the coherent absorption conditions in Fano-resonant dissipative coupled oscillators. The model treats on the same footing the weak and strong coupling regimes, and includes the critical coupling concept, which is of great relevance in numerous applications; in addition, the role of asymmetry is thoroughly analyzed. Due to the wide generality of the model, which can be adapted to various frameworks like nanophotonics, plasmonics, and optomechanics, we envisage that the analytical formulas presented here will be crucial to effectively design devices and to interpret experimental results.
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Affiliation(s)
- Simone Zanotto
- Istituto Nazionale di Ottica - CNR, Via Nello Carrara 1, 50019 Sesto Fiorentino (FI), Italy
| | - Alessandro Tredicucci
- NEST, Istituto Nanoscienze - CNR, P.za S. Silvestro 12, 56127 Pisa, Italy.,Dipartimento di Fisica "E. Fermi", Università di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy
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22
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Viti L, Hu J, Coquillat D, Knap W, Tredicucci A, Politano A, Vitiello MS. Black Phosphorus Terahertz Photodetectors. Adv Mater 2015; 27:5567-72. [PMID: 26270791 DOI: 10.1002/adma.201502052] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 07/08/2015] [Indexed: 05/15/2023]
Abstract
The first room-temperature terahertz (THz)-frequency nanodetector exploiting a 10 nm thick flake of exfoliated crystalline black phosphorus as an active channel of a field-effect transistor, is devised. By engineering and embedding planar THz antennas for efficient light harvesting, the first technological demonstration of a phosphorus-based active THz device is described.
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Affiliation(s)
- Leonardo Viti
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, I-56127, Italy
| | - Jin Hu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, 70118, USA
| | - Dominique Coquillat
- Laboratoire Charles Coulomb (L2C), UMR 5221 CNRS-Université de Montpellier, Montpellier, F-34095, France
| | - Wojciech Knap
- Laboratoire Charles Coulomb (L2C), UMR 5221 CNRS-Université de Montpellier, Montpellier, F-34095, France
- Institute of High Pressure Physics, Polish Academy of Sciences, ul. Sokolowska, 01-142, Warsaw, Poland
| | | | - Antonio Politano
- Dipartimento di Fisica, Università degli Studi della Calabria, via Ponte Bucci, 87036, Rende, (CS), Italy
| | - Miriam Serena Vitiello
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, I-56127, Italy
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23
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Bianco F, Miseikis V, Convertino D, Xu JH, Castellano F, Beere HE, Ritchie DA, Vitiello MS, Tredicucci A, Coletti C. THz saturable absorption in turbostratic multilayer graphene on silicon carbide. Opt Express 2015; 23:11632-11640. [PMID: 25969255 DOI: 10.1364/oe.23.011632] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We investigated the room-temperature Terahertz (THz) response as saturable absorber of turbostratic multilayer graphene grown on the carbon-face of silicon carbide. By employing an open-aperture z-scan method and a 2.9 THz quantum cascade laser as source, a 10% enhancement of transparency is observed. The saturation intensity is several W/cm2, mostly attributed to the Pauli blocking effect in the intrinsic graphene layers. A visible increase of the modulation depth as a function of the number of graphene sheets was recorded as consequence of the low nonsaturable losses. The latter in turn revealed that crystalline disorder is the main limitation to larger modulations, demonstrating that the THz nonlinear absorption properties of turbostratic graphene can be engineered via a proper control of the crystalline disorder and the layers number.
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24
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Baldacci L, Zanotto S, Biasiol G, Sorba L, Tredicucci A. Interferometric control of absorption in thin plasmonic metamaterials: general two port theory and broadband operation. Opt Express 2015; 23:9202-9210. [PMID: 25968754 DOI: 10.1364/oe.23.009202] [Citation(s) in RCA: 3] [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: 06/04/2023]
Abstract
In order to extend the Coherent Perfect Absorption (CPA) phenomenology to broadband operation, the interferometric control of absorption is investigated in two-port systems without port permutation symmetry. Starting from the two-port theory of CPA treated within the Scattering Matrix formalism, we demonstrate that for all linear two-port systems with reciprocity the absorption is represented by an ellipse as function of the relative phase and intensity of the two input beams, and it is uniquely determined by the device single-beam reflectance and transmittance, and by the dephasing of the output beams. The basic properties of the phenomenon in systems without port permutation symmetry show that CPA conditions can still be found in such asymmetric devices, while the asymmetry can be beneficial for broadband operation. As experimental proof, we performed transmission measurements on a metal-semiconductor metamaterial, employing a Mach-Zehnder interferometer. The experimental results clearly evidence the elliptical feature of absorption and trace a route towards broadband operation.
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25
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Ferrari AC, Bonaccorso F, Fal'ko V, Novoselov KS, Roche S, Bøggild P, Borini S, Koppens FHL, Palermo V, Pugno N, Garrido JA, Sordan R, Bianco A, Ballerini L, Prato M, Lidorikis E, Kivioja J, Marinelli C, Ryhänen T, Morpurgo A, Coleman JN, Nicolosi V, Colombo L, Fert A, Garcia-Hernandez M, Bachtold A, Schneider GF, Guinea F, Dekker C, Barbone M, Sun Z, Galiotis C, Grigorenko AN, Konstantatos G, Kis A, Katsnelson M, Vandersypen L, Loiseau A, Morandi V, Neumaier D, Treossi E, Pellegrini V, Polini M, Tredicucci A, Williams GM, Hong BH, Ahn JH, Kim JM, Zirath H, van Wees BJ, van der Zant H, Occhipinti L, Di Matteo A, Kinloch IA, Seyller T, Quesnel E, Feng X, Teo K, Rupesinghe N, Hakonen P, Neil SRT, Tannock Q, Löfwander T, Kinaret J. Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems. Nanoscale 2015; 7:4598-810. [PMID: 25707682 DOI: 10.1039/c4nr01600a] [Citation(s) in RCA: 976] [Impact Index Per Article: 108.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We present the science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems, targeting an evolution in technology, that might lead to impacts and benefits reaching into most areas of society. This roadmap was developed within the framework of the European Graphene Flagship and outlines the main targets and research areas as best understood at the start of this ambitious project. We provide an overview of the key aspects of graphene and related materials (GRMs), ranging from fundamental research challenges to a variety of applications in a large number of sectors, highlighting the steps necessary to take GRMs from a state of raw potential to a point where they might revolutionize multiple industries. We also define an extensive list of acronyms in an effort to standardize the nomenclature in this emerging field.
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Affiliation(s)
- Andrea C Ferrari
- Cambridge Graphene Centre, University of Cambridge, Cambridge, CB3 0FA, UK.
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26
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Pitanti A, Fink JM, Safavi-Naeini AH, Hill JT, Lei CU, Tredicucci A, Painter O. Strong opto-electro-mechanical coupling in a silicon photonic crystal cavity. Opt Express 2015; 23:3196-3208. [PMID: 25836178 DOI: 10.1364/oe.23.003196] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We fabricate and characterize a microscale silicon opto-electromechanical system whose mechanical motion is coupled capacitively to an electrical circuit and optically via radiation pressure to a photonic crystal cavity. To achieve large electromechanical interaction strength, we implement an inverse shadow mask fabrication scheme which obtains capacitor gaps as small as 30 nm while maintaining a silicon surface quality necessary for minimizing optical loss. Using the sensitive optical read-out of the photonic crystal cavity, we characterize the linear and nonlinear capacitive coupling to the fundamental ω(m)/2π = 63 MHz in-plane flexural motion of the structure, showing that the large electromechanical coupling in such devices may be suitable for realizing efficient microwave-to-optical signal conversion.
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Clericò V, Masini L, Boni A, Meucci S, Cecchini M, Recchia FA, Tredicucci A, Bifone A. Water-dispersible three-dimensional LC-nanoresonators. PLoS One 2014; 9:e105474. [PMID: 25153993 PMCID: PMC4143276 DOI: 10.1371/journal.pone.0105474] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Accepted: 07/21/2014] [Indexed: 12/03/2022] Open
Abstract
Nanolithography techniques enable the fabrication of complex nanodevices that can be used for biosensing purposes. However, these devices are normally supported by a substrate and their use is limited to in vitro applications. Following a top-down procedure, we designed and fabricated composite inductance-capacitance (LC) nanoresonators that can be detached from their substrate and dispersed in water. The multimaterial composition of these resonators makes it possible to differentially functionalize different parts of the device to obtain stable aqueous suspensions and multi-sensing capabilities. For the first time, we demonstrate detection of these devices in an aqueous environment, and we show that they can be sensitized to their local environment and to chemical binding of specific molecular moieties. The possibility to optically probe the nanoresonator resonance in liquid dispersions paves the way to a variety of new applications, including injection into living organisms for in vivo sensing and imaging.
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Affiliation(s)
- Vito Clericò
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Pisa, Italy
- * E-mail: (AB); (VC)
| | - Luca Masini
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Pisa, Italy
- NEST, CNR-Istituto Nanoscienze and Scuola Normale Superiore, Pisa, Italy
| | - Adriano Boni
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Pisa, Italy
| | - Sandro Meucci
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Pisa, Italy
- NEST, CNR-Istituto Nanoscienze and Scuola Normale Superiore, Pisa, Italy
| | - Marco Cecchini
- NEST, CNR-Istituto Nanoscienze and Scuola Normale Superiore, Pisa, Italy
| | - Fabio A. Recchia
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
- Department of Physiology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | | | - Angelo Bifone
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Pisa, Italy
- * E-mail: (AB); (VC)
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28
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Meucci S, Travagliati M, Vittorio O, Cirillo G, Masini L, Voliani V, Picci N, Beltram F, Tredicucci A, Cecchini M. Tubeless biochip for chemical stimulation of cells in closed-bioreactors: anti-cancer activity of the catechin–dextran conjugate. RSC Adv 2014. [DOI: 10.1039/c4ra05496b] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Here we introduce a tubeless microbioreactor for chemically stimulation of cells in microchambers, based on automatic cell valving, hydrostatic-pressure pumping and on-chip liquid reservoirs.
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Affiliation(s)
- Sandro Meucci
- NEST
- Scuola Normale Superiore and Istituto Nanoscienze-CNR
- Pisa 56127, Italy
- Center for Nanotechnology Innovation@NEST
- Istituto Italiano di Tecnologia
| | - Marco Travagliati
- NEST
- Scuola Normale Superiore and Istituto Nanoscienze-CNR
- Pisa 56127, Italy
- Center for Nanotechnology Innovation@NEST
- Istituto Italiano di Tecnologia
| | - Orazio Vittorio
- NEST
- Scuola Normale Superiore and Istituto Nanoscienze-CNR
- Pisa 56127, Italy
| | - Giuseppe Cirillo
- Department of Pharmacy
- Health and Nutritional Sciences
- University of Calabria
- I-87036 Rende (CS), Italy
- Leibniz Institute for Solid State and Materials Research Dresden
| | - Luca Masini
- NEST
- Scuola Normale Superiore and Istituto Nanoscienze-CNR
- Pisa 56127, Italy
- Center for Nanotechnology Innovation@NEST
- Istituto Italiano di Tecnologia
| | - Valerio Voliani
- NEST
- Scuola Normale Superiore and Istituto Nanoscienze-CNR
- Pisa 56127, Italy
- Center for Nanotechnology Innovation@NEST
- Istituto Italiano di Tecnologia
| | - Nevio Picci
- Department of Pharmacy
- Health and Nutritional Sciences
- University of Calabria
- I-87036 Rende (CS), Italy
| | - Fabio Beltram
- NEST
- Scuola Normale Superiore and Istituto Nanoscienze-CNR
- Pisa 56127, Italy
- Center for Nanotechnology Innovation@NEST
- Istituto Italiano di Tecnologia
| | | | - Marco Cecchini
- NEST
- Scuola Normale Superiore and Istituto Nanoscienze-CNR
- Pisa 56127, Italy
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29
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Romeo L, Coquillat D, Pea M, Ercolani D, Beltram F, Sorba L, Knap W, Tredicucci A, Vitiello MS. Nanowire-based field effect transistors for terahertz detection and imaging systems. Nanotechnology 2013; 24:214005. [PMID: 23618953 DOI: 10.1088/0957-4484/24/21/214005] [Citation(s) in RCA: 7] [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] [Indexed: 06/02/2023]
Abstract
The development of self-assembled nanostructure technologies has recently opened the way towards a wide class of semiconductor integrated devices, with progressively optimized performances and the potential for a widespread range of electronic and photonic applications. Here we report on the development of field effect transistors (FETs) based on semiconductor nanowires (NWs) as highly-sensitive room-temperature plasma-wave broadband terahertz (THz) detectors. The electromagnetic radiation at 0.3 THz is funneled onto a broadband bow-tie antenna, whose lobes are connected to the source and gate FET electrodes. The oscillating electric field experienced by the channel electrons, combined with the charge density modulation by the gate electrode, results in a source-drain signal rectification, which can be read as a DC signal output. We investigated the influence of Se-doping concentration of InAs NWs on the detection performances, reaching responsivity values higher than 100 V W⁻¹, with noise-equivalent-power of ∼10⁻⁹ W Hz(⁻½). Transmission imaging experiments at 0.3 THz show the good reliability and sensitivity of the devices in a real practical application.
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Affiliation(s)
- L Romeo
- NEST, Scuola Normale Superiore and CNR-Istituto Nanoscienze, Piazza San Silvestro 12, I-56127 Pisa, Italy.
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30
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Knap W, Rumyantsev S, Vitiello MS, Coquillat D, Blin S, Dyakonova N, Shur M, Teppe F, Tredicucci A, Nagatsuma T. Nanometer size field effect transistors for terahertz detectors. Nanotechnology 2013; 24:214002. [PMID: 23618776 DOI: 10.1088/0957-4484/24/21/214002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Nanometer size field effect transistors can operate as efficient resonant or broadband terahertz detectors, mixers, phase shifters and frequency multipliers at frequencies far beyond their fundamental cut-off frequency. This work is an overview of some recent results concerning the application of nanometer scale field effect transistors for the detection of terahertz radiation.
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Affiliation(s)
- W Knap
- Laboratoire Charles Coulomb, UMR 5221, Université Montpellier 2 and CNRS, F-34950 Montpellier, France.
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31
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Ménard J, Porer M, Leitenstorfer A, Huber R, Degl'Innocenti R, Zanotto S, Biasiol G, Sorba L, Tredicucci A. Sub-cycle switching of a photonic bandstructure via ultrastrong light-matter coupling. EPJ Web of Conferences 2013. [DOI: 10.1051/epjconf/20134109009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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32
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Vicarelli L, Vitiello MS, Coquillat D, Lombardo A, Ferrari AC, Knap W, Polini M, Pellegrini V, Tredicucci A. Graphene field-effect transistors as room-temperature terahertz detectors. Nat Mater 2012; 11:865-71. [PMID: 22961203 DOI: 10.1038/nmat3417] [Citation(s) in RCA: 256] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 08/03/2012] [Indexed: 05/22/2023]
Abstract
The unique optoelectronic properties of graphene make it an ideal platform for a variety of photonic applications, including fast photodetectors, transparent electrodes in displays and photovoltaic modules, optical modulators, plasmonic devices, microcavities, and ultra-fast lasers. Owing to its high carrier mobility, gapless spectrum and frequency-independent absorption, graphene is a very promising material for the development of detectors and modulators operating in the terahertz region of the electromagnetic spectrum (wavelengths in the hundreds of micrometres), still severely lacking in terms of solid-state devices. Here we demonstrate terahertz detectors based on antenna-coupled graphene field-effect transistors. These exploit the nonlinear response to the oscillating radiation field at the gate electrode, with contributions of thermoelectric and photoconductive origin. We demonstrate room temperature operation at 0.3 THz, showing that our devices can already be used in realistic settings, enabling large-area, fast imaging of macroscopic samples.
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Affiliation(s)
- L Vicarelli
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
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33
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de Cumis US, Xu JH, Masini L, Degl'innocenti R, Pingue P, Beltram F, Tredicucci A, Vitiello MS, Benedetti PA, Beere HE, Ritchie DA. Terahertz confocal microscopy with a quantum cascade laser source. Opt Express 2012; 20:21924-31. [PMID: 23037342 DOI: 10.1364/oe.20.021924] [Citation(s) in RCA: 7] [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] [Indexed: 05/08/2023]
Abstract
We report on the implementation of a confocal microscopy system based on a 2.9 THz quantum cascade laser source. Lateral and axial resolutions better than 70 μm and 400 μm, respectively, are achieved, with a large contrast enhancement compared to the non-confocal arrangement. The capability of resolving overlapping objects lying on different longitudinal planes is also clearly demonstrated.
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Affiliation(s)
- Ugo Siciliani de Cumis
- NEST, CNR-Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy.
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34
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Viti L, Vitiello MS, Ercolani D, Sorba L, Tredicucci A. Se-doping dependence of the transport properties in CBE-grown InAs nanowire field effect transistors. Nanoscale Res Lett 2012; 7:159. [PMID: 22373361 PMCID: PMC3311085 DOI: 10.1186/1556-276x-7-159] [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] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 02/28/2012] [Indexed: 05/23/2023]
Abstract
We investigated the transport properties of lateral gate field effect transistors (FET) that have been realized by employing, as active elements, (111) B-oriented InAs nanowires grown by chemical beam epitaxy with different Se-doping concentrations. On the basis of electrical measurements, it was found that the carrier mobility increases from 103 to 104 cm2/(V × sec) by varying the ditertiarybutyl selenide (DtBSe) precursor line pressure from 0 to 0.4 Torr, leading to an increase of the carrier density in the transistor channel of more than two orders of magnitude. By keeping the DtBSe line pressure at 0.1 Torr, the carrier density in the nanowire channel measures ≈ 5 × 1017 cm-3 ensuring the best peak transconductances (> 100 mS/m) together with very low resistivity values (70 Ω × μm) and capacitances in the attofarad range. These results are particularly relevant for further optimization of the nanowire-FET terahertz detectors recently demonstrated.PACS: 73.63.-b, 81.07.Gf, 85.35.-p.
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Affiliation(s)
- Leonardo Viti
- NEST, Istituto Nanoscienze-Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, 56127, Italy
| | - Miriam S Vitiello
- NEST, Istituto Nanoscienze-Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, 56127, Italy
| | - Daniele Ercolani
- NEST, Istituto Nanoscienze-Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, 56127, Italy
| | - Lucia Sorba
- NEST, Istituto Nanoscienze-Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, 56127, Italy
| | - Alessandro Tredicucci
- NEST, Istituto Nanoscienze-Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, 56127, Italy
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35
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Vitiello MS, Coquillat D, Viti L, Ercolani D, Teppe F, Pitanti A, Beltram F, Sorba L, Knap W, Tredicucci A. Room-temperature terahertz detectors based on semiconductor nanowire field-effect transistors. Nano Lett 2012; 12:96-101. [PMID: 22149118 DOI: 10.1021/nl2030486] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The growth of semiconductor nanowires (NWs) has recently opened new paths to silicon integration of device families such as light-emitting diodes, high-efficiency photovoltaics, or high-responsivity photodetectors. It is also offering a wealth of new approaches for the development of a future generation of nanoelectronic devices. Here we demonstrate that semiconductor nanowires can also be used as building blocks for the realization of high-sensitivity terahertz detectors based on a 1D field-effect transistor configuration. In order to take advantage of the low effective mass and high mobilities achievable in III-V compounds, we have used InAs nanowires, grown by vapor-phase epitaxy, and properly doped with selenium to control the charge density and to optimize source-drain and contact resistance. The detection mechanism exploits the nonlinearity of the transfer characteristics: the terahertz radiation field is fed at the gate-source electrodes with wide band antennas, and the rectified signal is then read at the output in the form of a DC drain voltage. Significant responsivity values (>1 V/W) at 0.3 THz have been obtained with noise equivalent powers (NEP) < 2 × 10(-9) W/(Hz)(1/2) at room temperature. The large existing margins for technology improvements, the scalability to higher frequencies, and the possibility of realizing multipixel arrays, make these devices highly competitive as a future solution for terahertz detection.
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Affiliation(s)
- Miriam S Vitiello
- Istituto di Fisica Applicata Nello Carrara - CNR, Via Madonna del Piano 1, Sesto Fiorentino, I-50019 Italy.
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36
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Vitiello MS, Xu JH, Kumar M, Beltram F, Tredicucci A, Mitrofanov O, Beere HE, Ritchie DA. High efficiency coupling of Terahertz micro-ring quantum cascade lasers to the low-loss optical modes of hollow metallic waveguides. Opt Express 2011; 19:1122-1130. [PMID: 21263652 DOI: 10.1364/oe.19.001122] [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: 05/30/2023]
Abstract
We demonstrate that azimuthally polarized surface emitting Terahertz quantum cascade lasers fabricated in a micro-ring resonator geometry can be coupled to cylindrical hollow aluminum waveguides reaching efficiencies as high ≈98%, when a collimating lens is used. By placing the waveguide in close contact with the QCL in a simple back-to-back geometry, the laser mode can be perfectly matched with the low loss TE(01) waveguide mode showing attenuation losses as low as ≈2.3-2.7 dB/m at 3.2 THz.
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Affiliation(s)
- Miriam S Vitiello
- CNR-Istituto Nazionale di Fisica Applicata Nello Carrara, Sesto Fiorentino, Italy.
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37
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Mahler L, Tredicucci A, Beltram F, Beere HE, Ritchie DA. Tuning a distributed feedback laser with a coupled microcavity. Opt Express 2010; 18:19185-19191. [PMID: 20940814 DOI: 10.1364/oe.18.019185] [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: 05/30/2023]
Abstract
We show that a distributed-feedback terahertz quantum cascade laser can be tuned with a coupled microcavity by anti-crossing of the respective eigenfrequencies. In this proof-of-concept experiment, a tuning range of 20 GHz is obtained, in good agreement with a simple finite element model, which shows that the tuning is determined by the coupling strength between the resonators. The concept could be applied to any laser cavity, but becomes progressively more attractive the lower the emission frequency.
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Affiliation(s)
- Lukas Mahler
- NEST, Istituto Nanoscienze--CNR and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127, Pisa, Italy
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38
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Degl'Innocenti R, Montinaro M, Xu J, Piazza V, Pingue P, Tredicucci A, Beltram F, Beere HE, Ritchie DA. Differential near-field scanning optical microscopy with THz quantum cascade laser sources. Opt Express 2009; 17:23785-23792. [PMID: 20052089 DOI: 10.1364/oe.17.023785] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have realized a differential Near-field Scanning Optical Microscope (NSOM) working with subwavelength resolution in the THz spectral region. The system employs a quantum cascade laser emitting at lambda approximately 105 microm as source, and the method, differently from conventional NSOM, involves diffracting apertures with size comparable to the wavelength. This concept ensures a higher signal-to-noise level at the expense of an additional computational step. In the implementation here reported lambda/10 resolution has been achieved; present limiting factors are investigated through finite difference time domain simulations.
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Affiliation(s)
- R Degl'Innocenti
- NEST, CNR-INFM and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy.
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39
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Hensley JM, Montoya J, Allen MG, Xu J, Mahler L, Tredicucci A, Beere HE, Ritchie DA. Spectral behavior of a terahertz quantum-cascade laser. Opt Express 2009; 17:20476-20483. [PMID: 19997276 DOI: 10.1364/oe.17.020476] [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: 05/28/2023]
Abstract
In this paper, the spectral behavior of two terahertz (THz) quantum cascade lasers (QCLs) operating both pulsed and cw is characterized using a heterodyne technique. Both lasers emitting around 2.5 THz are combined onto a whisker contact Schottky diode mixer mounted in a corner cube reflector. The resulting difference frequency beatnote is recorded in both the time and frequency domain. From the frequency domain data, we measure the effective laser linewidth and the tuning rates as a function of both temperature and injection current and show that the current tuning behavior cannot be explained by temperature tuning mechanisms alone. From the time domain data, we characterize the intrapulse frequency tuning behavior, which limits the effective linewidth to approximately 5 MHz.
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Affiliation(s)
- J M Hensley
- Physical Sciences Inc, 20 New England Business Center, Andover, Massachusetts 01810-1077, USA.
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40
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Tredicucci A. Quantum dots: Long life in zero dimensions. Nat Mater 2009; 8:775-776. [PMID: 19773786 DOI: 10.1038/nmat2541] [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: 05/28/2023]
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41
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Willer U, Pohlkötter A, Schade W, Xu J, Losco T, Green RP, Tredicucci A, Beere HE, Ritchie DA. Resonant tuning fork detector for THz radiation. Opt Express 2009; 17:14069-14074. [PMID: 19654815 DOI: 10.1364/oe.17.014069] [Citation(s) in RCA: 2] [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: 05/28/2023]
Abstract
THz-sensing is an emerging technology that would be advantageous for a variety of applications in industry, biology, biochemistry and security, if small and convenient to use sources and detectors would be readily available. However, most of them are bulky, complicate to operate, and need cryogenic cooling. Here we present a new detection scheme that is versatile enough to detect electro-magnetic radiation within the whole spectrum, can be easily applied to the THz-range, and operates at room temperature. The mechanism is based on the resonant excitation of a quartz tuning fork.
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Affiliation(s)
- Ulrike Willer
- Clausthal University of Technology, LaserApplicationCenter, Am Stollen 19/Haus3,38640 Goslar, Germany.
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42
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Mahler L, Amanti MI, Walther C, Tredicucci A, Beltram F, Faist J, Beere HE, Ritchie DA. Distributed feedback ring resonators for vertically emitting terahertz quantum cascade lasers. Opt Express 2009; 17:13031-13039. [PMID: 19654707 DOI: 10.1364/oe.17.013031] [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: 05/28/2023]
Abstract
We present distributed-feedback Terahertz quantum cascade lasers operating in a double-metal ring waveguide. High power collimated emission in a single spectral mode is observed in the vertical direction. A double-slit configuration is employed to achieve both good electrical contacts and efficient power out-coupling. The optical properties of the devices are interpreted with the aid of finite element simulations.
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Affiliation(s)
- Lukas Mahler
- NEST, CNR-INFM and Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126, Pisa, Italy.
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Richter H, Semenov AD, Pavlov SG, Mahler L, Tredicucci A, Beere HE, Ritchie DA, Ortolani M, Schade U, Il'in KS, Siegel M, Hübers HW. Development of a THz heterodyne receiver with quantum cascade laser and hot electron bolometer mixer for standoff detection of explosive material. ACTA ACUST UNITED AC 2009. [DOI: 10.1117/12.818134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Mahler L, Tredicucci A, Beltram F, Walther C, Beere HE, Ritchie DA. Finite size effects in surface emitting Terahertz quantum cascade lasers. Opt Express 2009; 17:6703-6709. [PMID: 19365498 DOI: 10.1364/oe.17.006703] [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: 05/27/2023]
Abstract
We analyze surface-emitting distributed feedback resonators for Terahertz quantum cascade lasers fabricated from double-metal waveguides. We explain the influence on resonances and surface-emission properties of the finite length and width of the gratings in connection with absorbing boundary conditions, and show that, contrary to the infinite case, the modes on either side of the photonic band-gap have finite surface losses. The lateral design of the resonator is shown to be important to avoid transverse modes of higher order and anti-guiding effects. Experimental findings are indeed in excellent agreement with the simulations. Both modeling and fabrication can easily be applied to arbitrary gratings, of which we discuss here a first interesting example.
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Affiliation(s)
- Lukas Mahler
- NEST CNR-INFM, Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126, Pisa, Italy.
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Günter G, Anappara AA, Hees J, Sell A, Biasiol G, Sorba L, De Liberato S, Ciuti C, Tredicucci A, Leitenstorfer A, Huber R. Sub-cycle switch-on of ultrastrong light–matter interaction. Nature 2009; 458:178-81. [DOI: 10.1038/nature07838] [Citation(s) in RCA: 437] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Accepted: 01/20/2009] [Indexed: 11/09/2022]
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Demichel O, Mahler L, Losco T, Mauro C, Green R, Tredicucci A, Xu J, Beltram F, Beere HE, Ritchie DA, Tamosinuas V. Surface plasmon photonic structures in terahertz quantum cascade lasers. Opt Express 2006; 14:5335-5345. [PMID: 19516700 DOI: 10.1364/oe.14.005335] [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: 05/27/2023]
Abstract
The periodic scattering of the surface plasmon modes employed in the waveguide of terahertz quantum cascade lasers is shown to be an efficient method to control the properties of the laser emission. The scatterers are realized as thin slits in the metal and top contact layer carrying the surface plasmon. This technique provides larger coupling strengths than previously reported and can be used in various device implementations. Here the method is applied to realize a distributed feedback resonator without back-facet reflection, to achieve vertical emission of the radiation with second-order gratings, and to increase the facet reflectivity by fabricating passive distributed Bragg reflectors.
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Hübers HW, Pavlov S, Semenov A, Köhler R, Mahler L, Tredicucci A, Beere H, Ritchie D, Linfield E. Terahertz quantum cascade laser as local oscillator in a heterodyne receiver. Opt Express 2005; 13:5890-5896. [PMID: 19498595 DOI: 10.1364/opex.13.005890] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Terahertz quantum cascade lasers have been investigated with respect to their performance as a local oscillator in a heterodyne receiver. The beam profile has been measured and transformed in to a close to Gaussian profile resulting in a good matching between the field patterns of the quantum cascade laser and the antenna of a superconducting hot electron bolometric mixer. Noise temperature measurements with the hot electron bolometer and a 2.5 THz quantum cascade laser yielded the same result as with a gas laser as local oscillator.
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Affiliation(s)
- Alessandro Tredicucci
- NEST-INFM (National Enterprise for nanoScience and nanoTechnology of the Istituto Nazionale per la Fisica della Materia) and Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
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Köhler R, Tredicucci A, Beltram F, Beere HE, Linfield EH, Davies AG, Ritchie DA. Low-threshold quantum-cascade lasers at 3.5 THz (lambda = 85 microm). Opt Lett 2003; 28:810-812. [PMID: 12779154 DOI: 10.1364/ol.28.000810] [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: 05/24/2023]
Abstract
Chirped-superlattice quantum-cascade lasers are reported that emit at lambda approximately 85 microm (3.6 THz), which is to the authors' knowledge the longest wavelength demonstrated so far with this technology. Collected peak output powers of 1.5 mW per facet were measured at liquid-helium temperature, and a maximum operating temperature of 45 K was reached. Record low-threshold-current densities of 95 and 115 A cm(-2) were observed in pulsed and continuous-wave operation, respectively. For the latter, output powers of a few hundred microwatts are estimated at low temperatures.
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Affiliation(s)
- Rüdeger Köhler
- National Enterprise for nanoScience and nanoTechnology-Istituto Nazionale per la Fisica della Materia, Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
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Dini D, Köhler R, Tredicucci A, Biasiol G, Sorba L. Microcavity polariton splitting of intersubband transitions. Phys Rev Lett 2003; 90:116401. [PMID: 12688948 DOI: 10.1103/physrevlett.90.116401] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2002] [Indexed: 05/24/2023]
Abstract
The optical response of the intersubband excitation of multiple two-dimensional electron gases within a semiconductor microcavity has been studied through angle-dependent reflectance measurements. Using a resonator based on total internal reflection, a clear splitting of about 14 meV of the coupled intersubband cavity modes is observed from 10 K to room temperature, with resulting polaritonlike dispersion. The experimental findings are in good agreement with theoretical calculations performed in a transfer-matrix formalism.
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Affiliation(s)
- Dimitri Dini
- NEST-INFM and Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
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