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Morgan TA, Rudie J, Zamani-Alavijeh M, Kuchuk AV, Orishchin N, Alema F, Osinsky A, Sleezer R, Salamo G, Ware ME. Band Offsets of the MOCVD-Grown β-(Al 0.21Ga 0.79) 2O 3/β-Ga 2O 3 (010) Heterojunction. ACS Appl Mater Interfaces 2022; 14:33944-33951. [PMID: 35848769 DOI: 10.1021/acsami.2c04177] [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] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The band offsets for the β-(Al0.21Ga0.79)2O3/β-Ga2O3 (010) heterojunction have been experimentally measured by X-ray photoelectron spectroscopy. High-quality β-(Al0.21Ga0.79)2O3 films were grown by metal-organic chemical vapor deposition for characterization. The indirect band gap of β-(Al0.21Ga0.79)2O3 was determined by optical transmission to be 4.69 ± 0.03 eV with a direct transition of 5.37 ± 0.03 eV, while β-Ga2O3 was confirmed to have an indirect band gap of 4.52 ± 0.03 eV with a direct transition of 4.94 ± 0.03 eV. The resulting band alignment at the heterojunction was determined to be of type II with the valence and conduction band edges of β-(Al0.21Ga0.79)2O3 being -0.26 ± 0.08 and 0.43 ± 0.08 eV, respectively, above those of β-Ga2O3 (010). These values can now be used to help better design and predict the performance of β-(AlxGa1-x)2O3 heterojunction-based devices.
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Affiliation(s)
- Timothy A Morgan
- Institute for Nanoscience and Engineering, University of Arkansas, 731 W Dickson Street, Fayetteville, Arkansas 72701, United States
- Naval Surface Warfare Center Crane, 300 HWY 361, Crane, Indiana 47522, United States
| | - Justin Rudie
- Institute for Nanoscience and Engineering, University of Arkansas, 731 W Dickson Street, Fayetteville, Arkansas 72701, United States
| | - Mohammad Zamani-Alavijeh
- Institute for Nanoscience and Engineering, University of Arkansas, 731 W Dickson Street, Fayetteville, Arkansas 72701, United States
- Physics Department, University of Arkansas, 835 W Dickson Street, Fayetteville, Arkansas 72701, United States
| | - Andrian V Kuchuk
- Institute for Nanoscience and Engineering, University of Arkansas, 731 W Dickson Street, Fayetteville, Arkansas 72701, United States
| | - Nazar Orishchin
- Agnitron Technology Incorporated, Chanhassen, Minnesota 55317, United States
| | - Fikadu Alema
- Agnitron Technology Incorporated, Chanhassen, Minnesota 55317, United States
| | - Andrei Osinsky
- Agnitron Technology Incorporated, Chanhassen, Minnesota 55317, United States
| | - Robert Sleezer
- Twin Cities Engineering, Minnesota State University, Mankato, 9700 France Avenue, Suite P0820, Bloomington, Minnesota 55431, United States
| | - Gregory Salamo
- Institute for Nanoscience and Engineering, University of Arkansas, 731 W Dickson Street, Fayetteville, Arkansas 72701, United States
| | - Morgan E Ware
- Institute for Nanoscience and Engineering, University of Arkansas, 731 W Dickson Street, Fayetteville, Arkansas 72701, United States
- Department of Electrical Engineering, University of Arkansas, 4183 Bell Engineering Center, Fayetteville, Arkansas 72701, United States
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Ashalley E, Gryczynski K, Wang Z, Salamo G, Neogi A. Plasmonically-powered hot carrier induced modulation of light emission in a two-dimensional GaAs semiconductor quantum well. Nanoscale 2019; 11:3827-3836. [PMID: 30633286 DOI: 10.1039/c8nr07489e] [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: 06/09/2023]
Abstract
A hot-electron-enabled route to controlling light with dissipative loss compensation in semiconductor quantum light emitters has been realized for tunable quantum optoelectronic devices via a two-species plasmon system. The dual species nano-plasmonic system is achieved by combining UV-plasmonic gallium metal nanoparticles (GaNPs) with visible-plasmonic gold metal nanoparticles (AuNPs) on a near-infrared two-dimensional GaAs/AlGaAs quantum well emitter. It has been demonstrated that while hot carrier-powered charge-transfer processes can result in semiconductor doping and increased optical absorption, photo-generated carrier density in the quantum well can also be modulated by off-resonant plasmonic interaction without thermal dissipation. Merging these essential emitter-friendly optical characteristics in the two-species plasmon system, we effectively modulate the frequency of the emitted light. The wavelength of the emitted light is tuned by the plasmonically powered hot electron process induced by the AuNPs with a 10-fold emission enhancement induced by the GaNPs. The additional plasmonic element provides functionality to achieving an active plasmonic light emitter that is otherwise far from reach with conventional single plasmonic material-based semiconductors.
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Affiliation(s)
- Eric Ashalley
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 610054, China.
| | - Karol Gryczynski
- Department of Physics, University of North Texas, Denton, Texas 76203, USA.
| | - Zhiming Wang
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 610054, China.
| | - Gregory Salamo
- Department of Physics, University of Arkansas, Fayetteville, Arkansas, USA
| | - Arup Neogi
- Department of Physics, University of North Texas, Denton, Texas 76203, USA.
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Nima ZA, Vang KB, Nedosekin D, Kannarpady G, Saini V, Bourdo SE, Majeed W, Watanabe F, Darrigues E, Alghazali KM, Alawajji RA, Petibone D, Ali S, Biris AR, Casciano D, Ghosh A, Salamo G, Zharov V, Biris AS. Quantification of cellular associated graphene and induced surface receptor responses. Nanoscale 2019; 11:932-944. [PMID: 30608496 PMCID: PMC9261879 DOI: 10.1039/c8nr06847j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The use of graphene for biomedical and other applications involving humans is growing and shows practical promise. However, quantifying the graphitic nanomaterials that interact with cells and assessing any corresponding cellular response is extremely challenging. Here, we report an effective approach to quantify graphene interacting with single cells that utilizes combined multimodal-Raman and photoacoustic spectroscopy. This approach correlates the spectroscopic signature of graphene with the measurement of its mass using a quartz crystal microbalance resonator. Using this technique, we demonstrate single cell noninvasive quantification and multidimensional mapping of graphene with a detection limit of as low as 200 femtograms. Our investigation also revealed previously unseen graphene-induced changes in surface receptor expression in dendritic cells of the immune system. This tool integrates high-sensitivity real-time detection and monitoring of nanoscale materials inside single cells with the measurement of induced simultaneous biological cell responses, providing a powerful method to study the impact of nanomaterials on living systems and as a result, the toxicology of nanoscale materials.
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Affiliation(s)
- Zeid A Nima
- Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
| | - Kieng Bao Vang
- Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
| | - Dmitry Nedosekin
- Arkansas Nanomedicine Center, University of Arkansas for Medical Sciences, 4301W. Markham St, Little Rock, Arkansas 72205, USA.
| | - Ganesh Kannarpady
- Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
| | - Viney Saini
- Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
| | - Shawn E Bourdo
- Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
| | - Waqar Majeed
- Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
| | - Fumiya Watanabe
- Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
| | - Emilie Darrigues
- Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
| | - Karrer M Alghazali
- Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
| | - Raad A Alawajji
- Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
| | - Dayton Petibone
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Jefferson, AR 72079, USA
| | - Syed Ali
- Division of Neurotoxicology, National Center for Toxicological Research, Jefferson, AR 72079, USA
| | - Alexandru R Biris
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, RO-400293 Cluj-Napoca, Romania
| | - Daniel Casciano
- Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
| | - Anindya Ghosh
- Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
| | - Gregory Salamo
- Institute for Nanoscience and Engineering, University of Arkansas at Fayetteville, AR 72701, USA
| | - Vladimir Zharov
- Arkansas Nanomedicine Center, University of Arkansas for Medical Sciences, 4301W. Markham St, Little Rock, Arkansas 72205, USA.
| | - Alexandru S Biris
- Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 S. University Ave., Little Rock, AR 72204, USA.
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Liang B, Yuan Q, Su L, Wang Y, Guo Y, Wang S, Fu G, Marega E, Mazur YI, Ware ME, Salamo G. Correlation between photoluminescence and morphology for single layer self-assembled InGaAs/GaAs quantum dots. Opt Express 2018; 26:23107-23118. [PMID: 30184966 DOI: 10.1364/oe.26.023107] [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: 07/04/2018] [Accepted: 08/19/2018] [Indexed: 06/08/2023]
Abstract
Single layer self-assembled InGaAs quantum dots (QDs) are manipulated by using different arsenic species on GaAs (100) surface. The As4 molecules are experimentally observed to be more promising than As2 to promote the formation of one-dimensionally-aligned QD-chain arrays. The lateral alignment of QDs and the corresponding formation of dot chains are explained by the anisotropic surface kinetics in combination with the different reactivities of the two molecules with bonding sites on the GaAs (100) surface. Photoluminescence (PL) measurements demonstrate that the spectra of the QD-chains broaden to higher energy and increases in intensity with increasing excitation laser power. The PL band of the QD-chains also exhibits a 9 meV reduction in linewidth as temperature increases starting from 8 K. These observations confirm an efficient lateral coupling between neighboring QDs and thereafter polarized QD emission, whereas the randomly distributed QDs grown with As2 show no preferential polarization. Such QD-chains exhibiting anisotropic properties have the potential for nanophotonics applications like electro-optic modulators with very low drive voltage and ultra-wide bandwidth operation.
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5
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Zhang Y, Wu Y, Wang X, Fossum ER, Kumar R, Liu J, Salamo G, Yu SQ. Non-avalanche single photon detection without carrier transit-time delay through quantum capacitive coupling. Opt Express 2017; 25:26508-26518. [PMID: 29092140 DOI: 10.1364/oe.25.026508] [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] [Received: 07/12/2017] [Accepted: 10/09/2017] [Indexed: 06/07/2023]
Abstract
Searching for innovative approaches to detect single photons remains at the center of science and technology for decades. This paper proposes a zero transit-time, non-avalanche quantum capacitive photodetector to register single photons. In this detector, the absorption of a single photon changes the wave function of a single electron trapped in a quantum dot (QD), leading to a charge density redistribution nearby. This redistribution translates into a voltage signal through capacitive coupling between the QD and the measurement probe. Using InAs QD/AlAs barrier as a model system, the simulation shows that the output signal reaches ~4 mV per absorbed photon, promising for high-sensitivity, ps single-photon detection.
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Al Saqri NA, Felix JF, Aziz M, Kunets VP, Jameel D, Taylor D, Henini M, Abd El-Sadek MS, Furrow C, Ware ME, Benamara M, Mortazavi M, Salamo G. Investigation of electrically active defects in InGaAs quantum wire intermediate-band solar cells using deep-level transient spectroscopy technique. Nanotechnology 2017; 28:045707. [PMID: 27997370 DOI: 10.1088/1361-6528/28/4/045707] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
InGaAs quantum wire (QWr) intermediate-band solar cell-based nanostructures grown by molecular beam epitaxy are studied. The electrical and interface properties of these solar cell devices, as determined by current-voltage (I-V) and capacitance-voltage (C-V) techniques, were found to change with temperature over a wide range of 20-340 K. The electron and hole traps present in these devices have been investigated using deep-level transient spectroscopy (DLTS). The DLTS results showed that the traps detected in the QWr-doped devices are directly or indirectly related to the insertion of the Si δ-layer used to dope the wires. In addition, in the QWr-doped devices, the decrease of the solar conversion efficiencies at low temperatures and the associated decrease of the integrated external quantum efficiency through InGaAs could be attributed to detected traps E1QWR_D, E2QWR_D, and E3QWR_D with activation energies of 0.0037, 0.0053, and 0.041 eV, respectively.
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Affiliation(s)
- Noor Alhuda Al Saqri
- School of Physics and Astronomy, Nottingham Nanotechnology and Nanoscience Center, University of Nottingham, Nottingham NG7 2RD, UK. Department of Physics, College of Science, Box 36, Sultan Qaboos University, Al Khoud 123, Oman
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7
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Neogi A, Gryczynski K, Llopis A, Lin J, Main K, Shimada R, Wang Z, Lee J, Salamo G, Krokhin A. Metallic Nanodroplet Induced Coulomb Catalysis for Off-Resonant Plasmonic Enhancement of Photoemission in Semiconductors. ACS Omega 2016; 1:19-28. [PMID: 31457115 PMCID: PMC6640769 DOI: 10.1021/acsomega.6b00009] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 06/14/2016] [Indexed: 06/09/2023]
Abstract
The enhancement of light from semiconductors due to surface plasmons coupled resonantly to its emission is limited because of dissipation in the metal and is also restricted by the dielectric characteristics and homogeneity of the metal-semiconductor interface. We report a new mechanism based on electrostatic interactions of carriers and their image charges in metals to generate more photons from optical sources at frequencies that are off-resonant to the localized plasmon frequency. Coulomb catalysis of carrier accumulation resulting from the inhomogeneity of metal nanodroplets on a semiconductor's surface can result in an enhancement of light that is nondissipative and does not require resonant coupling of plasmons to the emission wavelength. The enhancement occurs because of an increase in the ratio of radiative to nonradiative recombination in the vicinity of metal nanoparticles. It is equally effective with any type of metal and enhances radiation at any frequency, a property that is of principal importance for the realization of widely tunable semiconductor emitters. This fundamental mechanism provides a new perspective for improving the efficiency of light emitters and controlling carrier concentration on the nanoscale. The structural characteristics of the hybrid metal-semiconductor emitters are studied using electron microscopy and atomic force microscopy. We demonstrate the electrostatic mechanism by studying steady-state and transient photoluminescence from two-dimensional semiconductors, such as GaAs/AlGAs quantum wells, and bulk semiconductors, such as ZnO thin films, emitting in the near-IR and UV wavelength regimes, respectively.
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Affiliation(s)
- Arup Neogi
- Institute
of Fundamental and Frontier Sciences, University
of Electronic Science and Technology of China, Chengdu 610054, P.R. China
- Department
of Physics, University of North Texas, 211 Avenue A, Denton, Texas 76203, United States
- Advanced
Materials Manufacturing Process Institute, UNT Discovery Park, 3940 North Elm Street, #E132, Denton, Texas 76207-7102, United States
| | - Karol Gryczynski
- Department
of Physics, University of North Texas, 211 Avenue A, Denton, Texas 76203, United States
| | - Antonio Llopis
- Department
of Physics, University of North Texas, 211 Avenue A, Denton, Texas 76203, United States
| | - Jie Lin
- Department
of Physics, University of North Texas, 211 Avenue A, Denton, Texas 76203, United States
| | - Kyle Main
- Department
of Physics, University of North Texas, 211 Avenue A, Denton, Texas 76203, United States
| | - Ryoko Shimada
- Department
of Physics and Mathematical Sciences, Japan
Women University, 2-8-1
Mejirodai, Bunkyo-ku, Tokyo 112-8681, Japan
| | - Zhiming Wang
- Institute
of Fundamental and Frontier Sciences, University
of Electronic Science and Technology of China, Chengdu 610054, P.R. China
| | - Jihoon Lee
- College
of Electronics and Information, Kwangwoon
University, 447-1 Wolgye-dong, Nowon-gu, Seoul 139-701, South Korea
| | - Gregory Salamo
- Department
of Physics, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Arkadii Krokhin
- Department
of Physics, University of North Texas, 211 Avenue A, Denton, Texas 76203, United States
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8
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Bellaiche MM, Salamo G, Henry R, Fologea D, Krueger E, Al Faouri R. Photoactivity of the Lysenin Protein. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.2091] [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: 10/23/2022] Open
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9
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Simmonds PJ, Yerino CD, Sun M, Liang B, Huffaker DL, Dorogan VG, Mazur Y, Salamo G, Lee ML. Tuning quantum dot luminescence below the bulk band gap using tensile strain. ACS Nano 2013; 7:5017-5023. [PMID: 23701255 DOI: 10.1021/nn400395y] [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] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Self-assembled quantum dots (SAQDs) grown under biaxial tension could enable novel devices by taking advantage of the strong band gap reduction induced by tensile strain. Tensile SAQDs with low optical transition energies could find application in the technologically important area of mid-infrared optoelectronics. In the case of Ge, biaxial tension can even cause a highly desirable crossover from an indirect- to a direct-gap band structure. However, the inability to grow tensile SAQDs without dislocations has impeded progress in these directions. In this article, we demonstrate a method to grow dislocation-free, tensile SAQDs by employing the unique strain relief mechanisms of (110)-oriented surfaces. As a model system, we show that tensile GaAs SAQDs form spontaneously, controllably, and without dislocations on InAlAs(110) surfaces. The tensile strain reduces the band gap in GaAs SAQDs by ~40%, leading to robust type-I quantum confinement and photoluminescence at energies lower than that of bulk GaAs. This method can be extended to other zinc blende and diamond cubic materials to form novel optoelectronic devices based on tensile SAQDs.
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Affiliation(s)
- Paul J Simmonds
- Department of Electrical Engineering, Yale University, P.O. Box 208284, New Haven, Connecticut 06520, USA.
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10
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Duchesne D, Rutkowska KA, Volatier M, Légaré F, Delprat S, Chaker M, Modotto D, Locatelli A, De Angelis C, Sorel M, Christodoulides DN, Salamo G, Arès R, Aimez V, Morandotti R. Second harmonic generation in AlGaAs photonic wires using low power continuous wave light. Opt Express 2011; 19:12408-12417. [PMID: 21716479 DOI: 10.1364/oe.19.012408] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report modal phase matched (MPM) second harmonic generation (SHG) in high-index contrast AlGaAs sub-micron ridge waveguides, by way of sub-mW continuous wave powers at telecommunication wavelengths. We achieve an experimental normalized conversion efficiency of ~14%/W/cm2, obtained through a careful sub-wavelength design supporting both the phase matching requirement and a significant overlap efficiency. Furthermore, the weak anomalous dispersion, robust fabrication technology and possible geometrical and thermal tuning of the device functionality enable a fully integrated multi-functional chip for several critical areas in telecommunications, including wavelength (time) division multiplexing and quantum entanglement.
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Affiliation(s)
- D Duchesne
- INRS-EMT, 1650 Boulevard Lionel Boulet, Varennes, Québec, J3X 1S2, Canada.
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11
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Li S, Jiang Y, Wu Z, Wu J, Ying Z, Wang Z, Li W, Salamo G. Origins of 1/f noise in nanostructure inclusion polymorphous silicon films. Nanoscale Res Lett 2011; 6:281. [PMID: 21711802 PMCID: PMC3211346 DOI: 10.1186/1556-276x-6-281] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2010] [Accepted: 04/04/2011] [Indexed: 05/21/2023]
Abstract
In this article, we report that the origins of 1/f noise in pm-Si:H film resistors are inhomogeneity and defective structure. The results obtained are consistent with Hooge's formula, where the noise parameter, αH, is independent of doping ratio. The 1/f noise power spectral density and noise parameter αH are proportional to the squared value of temperature coefficient of resistance (TCR). The resistivity and TCR of pm-Si:H film resistor were obtained through linear current-voltage measurement. The 1/f noise, measured by a custom-built noise spectroscopy system, shows that the power spectral density is a function of both doping ratio and temperature.
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Affiliation(s)
- Shibin Li
- State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, China
- Arkansas Institute for Nanoscale Materials Science and Engineering, University of Arkansas, Fayetteville, AR 72701, USA
| | - Yadong Jiang
- State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, China
| | - Zhiming Wu
- State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, China
| | - Jiang Wu
- Arkansas Institute for Nanoscale Materials Science and Engineering, University of Arkansas, Fayetteville, AR 72701, USA
| | - Zhihua Ying
- Department of Electronics and Information, Hang Zhou Dianzi University, Hangzhou, 310018, China
| | - Zhiming Wang
- Arkansas Institute for Nanoscale Materials Science and Engineering, University of Arkansas, Fayetteville, AR 72701, USA
| | - Wei Li
- State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, China
| | - Gregory Salamo
- Arkansas Institute for Nanoscale Materials Science and Engineering, University of Arkansas, Fayetteville, AR 72701, USA
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13
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Vasa P, Pomraenke R, Schwieger S, Mazur YI, Kunets V, Srinivasan P, Johnson E, Kihm JE, Kim DS, Runge E, Salamo G, Lienau C. Coherent exciton-surface-plasmon-polariton interaction in hybrid metal-semiconductor nanostructures. Phys Rev Lett 2008; 101:116801. [PMID: 18851308 DOI: 10.1103/physrevlett.101.116801] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 08/01/2008] [Indexed: 05/26/2023]
Abstract
We report measurements of a coherent coupling between surface plasmon polaritons (SPP) and quantum well excitons in a hybrid metal-semiconductor nanostructure. The hybrid structure is designed to optimize the radiative exciton-SPP interaction which is probed by low-temperature, angle-resolved, far-field reflectivity spectroscopy. As a result of the coupling, a significant shift of approximately 7 meV and an increase in broadening by approximately 4 meV of the quantum well exciton resonance are observed. The experiments are corroborated by a phenomenological coupled-oscillator model predicting coupling strengths as large as 50 meV in structures with optimized detunings between the coupled exciton and SPP resonances. Such a strong interaction can, e.g., be used to enhance the luminescence yield of semiconductor quantum structures or to amplify SPP waves.
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Affiliation(s)
- P Vasa
- Institut für Physik, Carl von Ossietzky Universität, D-26111 Oldenburg, Germany
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14
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Suntsov S, Makris KG, Christodoulides DN, Stegeman GI, Morandotti R, Volatier M, Aimez V, Arès R, Yang EH, Salamo G. Optical spatial solitons at the interface between two dissimilar periodic media: theory and experiment. Opt Express 2008; 16:10480-10492. [PMID: 18607461 DOI: 10.1364/oe.16.010480] [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: 05/26/2023]
Abstract
Discrete spatial solitons traveling along the interface between two dissimilar one-dimensional arrays of waveguides were observed for the first time. Two interface solitons were found theoretically, each one with a peak in a different boundary channel. One evolves into a soliton from a linear mode at an array separation larger than a critical separation where-as the second soliton always exhibits a power threshold. These solitons exhibited different power thresholds which depended on the characteristics of the two lattices. For excitation of single channels near and at the boundary, the evolution behavior with propagation distance indicates that the solitons peaked near and at the interface experience an attractive potential on one side of the boundary, and a repulsive one on the opposite side. The power dependence of the solitons at variable distance from the boundary was found to be quite different on opposite sides of the interface and showed evidence for soliton switching between channels with increasing input power.
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Affiliation(s)
- S Suntsov
- College of Optics and Photonics, CREOL & FPCE, University of Central Florida, 4000 Central Florida Blvd., Orlando, Florida 32816, USA
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15
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Taylor C, Marega E, Stach EA, Salamo G, Hussey L, Muñoz M, Malshe A. Directed self-assembly of quantum structures by nanomechanical stamping using probe tips. Nanotechnology 2008; 19:015301. [PMID: 21730527 DOI: 10.1088/0957-4484/19/01/015301] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We demonstrate that nanomechanically stamped substrates can be used as templates to pattern and direct the self-assembly of epitaxial quantum structures such as quantum dots. Diamond probe tips are used to indent or stamp the surface of GaAs(100) to create nanoscale volumes of dislocation-mediated deformation, which alter the growth surface strain. These strained sites act to bias nucleation, hence allowing for selective growth of InAs quantum dots. Patterns of quantum dots are observed to form above the underlying nanostamped template. The strain state of the patterned structures is characterized by micro-Raman spectroscopy. The potential of using nanoprobe tips as a quantum dot nanofabrication technology are discussed.
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Affiliation(s)
- Curtis Taylor
- Department of Mechanical Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
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16
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Suntsov S, Makris KG, Christodoulides DN, Stegeman GI, Morandotti R, Yang H, Salamo G, Sorel M. Power thresholds of families of discrete surface solitons. Opt Lett 2007; 32:3098-3100. [PMID: 17975609 DOI: 10.1364/ol.32.003098] [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: 05/25/2023]
Abstract
We have investigated both theoretically and experimentally the power threshold of discrete Kerr surface solitons at the interface between a discrete one-dimensional (1D) (waveguide array) and a continuous 1D (slab waveguide) AlGaAs medium. Decreasing power thresholds were predicted and measured for soliton trapping at sites with increasing distance from the boundary. The thresholds approached asymptotically the power required for a discrete soliton of equivalent width in an infinite lattice. The minimum threshold coincided with a minimum in the interchannel coupling strength.
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Affiliation(s)
- S Suntsov
- College of Optics and Photonics, CREOL and FPCE, University of Central Florida, Orlando 32816, USA
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17
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Chauvet M, Fu G, Salamo G. Assessment method for photo-induced waveguides. Opt Express 2006; 14:10726-10732. [PMID: 19529480 DOI: 10.1364/oe.14.010726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A method to probe the guiding characteristics of waveguides formed in real-time is proposed and evaluated. It is based on the analysis of the time dependent light distribution observed at the exit face of the waveguide while progressively altering its index profile and probed by a large diameter optical beam. A beam propagation method is used to model the observed dynamics. The technique is applied to retrieve the properties of soliton-induced waveguides.
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18
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Suntsov S, Makris KG, Christodoulides DN, Stegeman GI, Haché A, Morandotti R, Yang H, Salamo G, Sorel M. Observation of discrete surface solitons. Phys Rev Lett 2006; 96:063901. [PMID: 16605995 DOI: 10.1103/physrevlett.96.063901] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2005] [Indexed: 05/08/2023]
Abstract
We report the first observation of discrete optical surface solitons at the interface between a nonlinear self-focusing waveguide lattice and a continuous medium. The effect of power on the localization process of these optical self-trapped states at the edge of an AlGaAs waveguide array is investigated in detail. Our experimental results are in good agreement with theoretical predictions.
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Affiliation(s)
- S Suntsov
- College of Optics and Photonics, CREOL & FPCE, University of Central Florida, 4000 Central Florida Boulevard, Orlando, Florida 32816, USA
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19
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Meier J, Stegeman GI, Christodoulides DN, Morandotti R, Salamo G, Yang H, Sorel M, Silberberg Y, Aitchison JS. Incoherent blocker soliton interactions in Kerr waveguide arrays. Opt Lett 2005; 30:3174-6. [PMID: 16342711 DOI: 10.1364/ol.30.003174] [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: 05/05/2023]
Abstract
We have observed the incoherent interaction between a highly confined (blocker) soliton and wide, moving signal beams of a different wavelength in a one-dimensional discrete Kerr medium. Digital switching of the blocker solitons to successive adjacent channels was measured with increasing signal power via both one and two cascaded interactions in an AlGaAs waveguide array, operations equivalent to a reconfigurable three-output router.
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Affiliation(s)
- J Meier
- College of Optics & Photonics, Center for Research and Education in Optics and Lasers and Florida Photonics Center of Excellence, University of Central Florida, Orlando 32816, USA.
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20
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Abstract
We report the observation of large self-deflection of 2-D bright photorefractive solitons in LiNbO3 crystal under a dc applied field. Beam deflection as large as 300 microm after a 7 mm propagation distance is reported, leading to formation of curved 2-D waveguides. We attribute this large deflection to the low level of impurity acceptors present in the samples, as confirmed by numerical results from a time-dependent photorefractive model.
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Affiliation(s)
- M Chauvet
- Département d'Optique, Institut FEMTO-ST, UMR, CNRS, Université de Franche-Comté, 25030 Besancon, France.
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21
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Meier J, Stegeman GI, Christodoulides DN, Silberberg Y, Morandotti R, Yang H, Salamo G, Sorel M, Aitchison JS. Beam interactions with a blocker soliton in one-dimensional arrays. Opt Lett 2005; 30:1027-9. [PMID: 15906992 DOI: 10.1364/ol.30.001027] [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: 05/02/2023]
Abstract
We investigate experimentally and numerically the interaction of a highly localized, single-channel discrete soliton (blocker) with a wide, tilted beam in a one-dimensional AlGaAs array. In agreement with theory the blocker is observed to discretely shift its position by multiple channels, depending on the intensity and relative phase of the tilted beam.
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Affiliation(s)
- J Meier
- College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816, USA.
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22
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Meier J, Stegeman G, Christodoulides D, Morandotti R, Sorel M, Yang H, Salamo G, Aitchison J, Silberberg Y. Nonlinear beam interactions in 1D discrete Kerr systems. Opt Express 2005; 13:1797-1807. [PMID: 19495059 DOI: 10.1364/opex.13.001797] [Citation(s) in RCA: 5] [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 interaction between parallel beams in one-dimensional discrete Kerr systems has been investigated using arrays of coupled channel waveguides. The experiments were performed in AlGaAs waveguides at 1550 nm which corresponds to photon energies just below one half the semiconductor's bandgap. The input intensity and relative input phase between the input beams was varied and the output intensity patterns were recorded. Observed was behavior ranging from a linear response, to soliton interactions between moderately and then strongly localized spatial solitons. Finally the influence of multiphoton absorption and asymmetric beam inputs on these interactions was investigated at very high intensities.
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23
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Meier J, Stegeman GI, Christodoulides DN, Silberberg Y, Morandotti R, Yang H, Salamo G, Sorel M, Aitchison JS. Experimental observation of discrete modulational instability. Phys Rev Lett 2004; 92:163902. [PMID: 15169231 DOI: 10.1103/physrevlett.92.163902] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2003] [Indexed: 05/24/2023]
Abstract
We report the first experimental observation of modulation instability in a discrete optical nonlinear array.
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Affiliation(s)
- J Meier
- School of Optics/CREOL, University of Central Florida, Orlando, Florida 32816, USA
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24
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Saadeh S, Shultz J, Salamo G. Experimental observation of chirped continuous pulse-train soliton solutions to the Maxwell-Bloch equations. Opt Express 2001; 8:153-158. [PMID: 19417798 DOI: 10.1364/oe.8.000153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A frequency chirped continuous wave laser beam incident upon a resonant, two-level atomic absorber is seen to evolve into a Jacobi elliptic pulse-train solution to the Maxwell-Bloch equations. Experimental pulse-train envelopes are found in good agreement with numerical and analytical predictions.
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Abstract
We report the observation of high-intensity solitons in a bulk strontium barium niobate crystal. The solitons are observed by use of 8-ns optical pulses with optical intensities greater than 100 MW/cm(2). Each soliton forms and attains its minimum width after roughly ten pulses and reaches e(-1) of the steady-state width after the first pulse. We find good agreement between experimental observations and theoretical predictions for the soliton existence curve.
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Affiliation(s)
- K Kos
- Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA
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26
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Meng H, Salamo G, Segev M. Primarily isotropic nature of photorefractive screening solitons and the interactions between them. Opt Lett 1998; 23:897-899. [PMID: 18087376 DOI: 10.1364/ol.23.000897] [Citation(s) in RCA: 2] [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: 05/25/2023]
Abstract
We present experimental evidence demonstrating that the photorefractive-index change responsible for the formation of photorefractive spatial screening solitons and coherent collisions between them is primarily isotropic in nature, even though the photorefractive medium is inherently anisotropic.
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Abstract
We present an experimental study of coherent collisions between one-dimensional bright photorefractive screening solitons in a bulk strontium barium niobate crystal.
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Shih MF, Segev M, Salamo G. Circular waveguides induced by two-dimensional bright steady-state photorefractive spatial screening solitons. Opt Lett 1996; 21:931-934. [PMID: 19876208 DOI: 10.1364/ol.21.000931] [Citation(s) in RCA: 11] [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: 05/28/2023]
Abstract
We report what we believe is the first experimental observation of bright-soliton-induced two-dimensional waveguides. The waveguides are induced by two-dimensional photorefractive screening solitons, and their guiding properties, i.e., whether the waveguides are single mode or multimode, are controlled by adjustment of the soliton parameters.
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Kos K, Meng H, Salamo G, Shih M, Segev M, Valley GC. One-dimensional steady-state photorefractive screening solitons. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1996; 53:R4330-R4333. [PMID: 9964916 DOI: 10.1103/physreve.53.r4330] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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30
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Shih MF, Leach P, Segev M, Garrett MH, Salamo G, Valley GC. Two-dimensional steady-state photorefractive screening solitons. Opt Lett 1996; 21:324-326. [PMID: 19865393 DOI: 10.1364/ol.21.000324] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We study experimentally steady-state photorefractive screening solitons trapped in both transverse dimensionsand measure their beam profiles as they propagate throughout the crystal. The solitons are observed to be axially symmetric, and they self-bend. We characterize the soliton dependence on the optical intensity, appliedelectric-field strength, and beam diameter.
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31
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Morin M, Duree G, Salamo G, Segev M. Waveguides formed by quasi-steady-state photorefractive spatial solitons. Opt Lett 1995; 20:2066-2068. [PMID: 19862252 DOI: 10.1364/ol.20.002066] [Citation(s) in RCA: 20] [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: 05/28/2023]
Abstract
We show that a quasi-steady-state photorefractive spatial soliton forms a waveguide structure in the bulk of a photorefractive material. Although the optically induced waveguide is formed by a very low-power (microwatts) soliton beam, it can guide a powerful (watt) beam of a longer wavelength at which the medium is nonphotosensitive. Furthermore, the waveguide survives, either in the dark or when guiding the longerwavelength beam, for a long time after the soliton beam is turned off. We take advantage of the solitons' property of evolution from a relatively broad input beam into a narrow channel and show that the soliton induces a tapered waveguide (an optical funnel) that improves the coupling efficiency of light into the waveguiding structure.
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32
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Duree G, Morin M, Salamo G, Segev M, Crosignani B, Sharp E, Yariv A. Dark photorefractive spatial solitons and photorefractive vortex solitons. Phys Rev Lett 1995; 74:1978-1981. [PMID: 10057811 DOI: 10.1103/physrevlett.74.1978] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Segev M, Crosignani B, Porto PD, Yariv A, Duree G, Salamo G, Sharp E. Stability of photorefractive spatial solitons. Opt Lett 1994; 19:1296-1298. [PMID: 19855499 DOI: 10.1364/ol.19.001296] [Citation(s) in RCA: 12] [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: 05/28/2023]
Abstract
We present a theoretical analysis of the stability of photorefractive spatial solitons along with experimental results that show that the solitons are stable for small-scale perturbations but break down when the perturbations exhibit a transverse scale comparable with the soliton size (cross section).
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35
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Duree G, Salamo G, Segev M, Yariv A, Crosignani B, Porto PD, Sharp E. Dimensionality and size of photorefractive spatial solitons. Opt Lett 1994; 19:1195-1197. [PMID: 19855467 DOI: 10.1364/ol.19.001195] [Citation(s) in RCA: 13] [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: 05/28/2023]
Abstract
We study experimentally self-trapping of optical beams in photorefractive media and show that the trapping is inherently asymmetric with respect to the two (transverse) trapping dimensions. We also present experimental results that show how the sizes of the resultant photorefractive spatial solitons are independent (within their range of existence) of the amplitude of the externally applied electric field used to generate them.
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36
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Kukhtarev N, Dovgalenko G, Duree GC, Salamo G, Sharp EJ, Wechsler BA, Klein MB. Single beam polarization holographic grating recording. Phys Rev Lett 1993; 71:4330-4333. [PMID: 10055219 DOI: 10.1103/physrevlett.71.4330] [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: 05/23/2023]
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37
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Rodriguez J, Salamo G. Self-oscillation in BaTiO(3) using a multimode laser. Appl Opt 1987; 26:2260-2262. [PMID: 20489853 DOI: 10.1364/ao.26.002260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The effect of temporal coherence on the phenomena of self-oscillation in photorefractive materials is analyzed using multilongitudinal-mode argon-ion and helium-neon lasers. Observations demonstrate that self-oscillation is possible when the mirror-crystal separation is large compared to the laser coherence length. The observations are shown to agree with predictions based on the recurrence in the temporal coherence of a multilongitudinal-mode laser.
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Rodriguez J, Siahmakoun A, Salamo G. Bistability and optical switching in a total internal reflection phase conjugator. Appl Opt 1987; 26:2263-2265. [PMID: 20489854 DOI: 10.1364/ao.26.002263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We report the observation of bistability in a BaTiO(3) total internal reflection phase conjugator. The system makes use of the position of the crystal relative to the input field as the dynamic variable. Switching behavior, induced by intensity changes at the input, is also reported.
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Rodriguez J, Siahmakoun A, Salamo G, Miller MJ, Clark Iii WW, Wood GL, Sharp EJ, Neurgaonkar RR. BSKNN as a self-pumped phase conjugator. Appl Opt 1987; 26:1732-1736. [PMID: 20454397 DOI: 10.1364/ao.26.001732] [Citation(s) in RCA: 6] [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: 05/29/2023]
Abstract
Self-pumping has been observed in a cerium-doped Ba(2-x)Sr(x)K(1-y)Na(y)Nb(5)O(15) (BSKNN) crystal at four argonion laser wavelengths. Phase-conjugate reflectivities as high as 30% were measured with response times inversely proportional to the 0.5 power of the input intensity. The response time for beam fanning in the crystal was determined to be inversely proportional to the 0.82 power of the input intensity.
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