The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Byoung Yoon Kim - One of the best experts on this subject based on the ideXlab platform.
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Polarization coupling in a highly birefringent photonic crystal fiber by torsional acoustic wave.
Optics express, 2008Co-Authors: Kwang Jo Lee, Kee Suk Hong, Hyun-chul Park, Byoung Yoon KimAbstract:We demonstrate and analyze the acousto-optic coupling between two optical polarization modes of the LP(01) mode propagating in a highly birefringent photonic crystal fiber. The coupling is realized based on wavelength selective acousto-optic coupling by traveling torsional acoustic wave in an all-fiber tunable polarization filter configuration. The dispersion properties of the torsional acoustic wave in the photonic crystal fiber and the influence of axial non-uniformity in the modal birefringence on the filter transmission are discussed in detail.
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All-fiber tunable filter and laser based on two-mode fiber
Optics Letters, 1996Co-Authors: Seok Hyun Yun, In Kag Hwang, Byoung Yoon KimAbstract:We demonstrate an all-fiber acousto-optic tunable filter based on two-spatial-mode coupling, with improved ruggedness and efficiency, by using a new acoustic-transducer design. We use a rigorous modeling of the flexural acoustic wave to analyze the mode coupling with better accuracy. Using the acousto-optic tunable filter, we demonstrate a novel all-fiber tunable laser with a tuning range of more than 20 nm and a linewidth of 0.2 nm.
F. Ramaz - One of the best experts on this subject based on the ideXlab platform.
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Ultrafast acousto-optic imaging with ultrasonic plane waves
Optics Express, 2016Co-Authors: Jean-baptiste Laudereau, Alexander A Grabar, Jean Luc Gennisson, Mickael Tanter, F. RamazAbstract:Due to multiple light scattering inside biological tissues, deep non-invasive optical medical imaging is very challenging. Acousto-optic imaging is a technique coupling ultrasound and light that allows recovering optical contrast at depths of few centimeters with a millimeter resolution. Recent advances in acousto-optic imaging are using short focused ultra-sound pulses often averaged over several hundred or thousand pulses. As the pulsing rate of commercial probes is limited to about few ultrasound cycles every 100 µs, acquiring an acousto-optic image usually takes several tens of seconds due to the high number of acoustic pulses excitation. We propose here a new acousto-optic imaging technique based on the use of ultrasound plane waves instead of focused ones that allows increasing drastically the imaging rate.
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Detection of the tagged or untagged photons in acousto-optic imaging of thick highly scattering media by photorefractive adaptive holography
The European Physical Journal E, 2009Co-Authors: Michel Gross, F. Ramaz, Philippe Delaye, Gérald Roosen, Micheline Lesaffre, Albert Claude BoccaraAbstract:We propose an original adaptive wavefront holographic setup based on the photorefractive effect (PR), to make real-time measurements of acousto-optic signals in thick scattering media, with a high flux collection at high rates for breast tumor detection. We describe here our present state of the art and understanding on the problem of breast imaging with PR detection of the acousto-optic signal.
G.h. Song - One of the best experts on this subject based on the ideXlab platform.
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Time-dependent analysis of acousto-optic tunable filters for multichannel optical switching
Journal of Lightwave Technology, 1997Co-Authors: G.h. SongAbstract:A time-dependent analysis of acousto-optic tunable filters (AOTF's) for multiwavelength optical-switching operations is presented, it explains the reason for the observed nonlinear behavior such as passband-pulling and quantifies the associated crosstalk performance degradation. The degradation of the filter performance is found to be due to copresence of the acousto-optic interaction profiles for different channels. Along with extensive Poincare-sphere analysis, the model also reveals time-dependent fluctuation of switching spectral responses, which calls for attention to the worst instances in the fluctuation for the wavelength division multiplexer (WDM) optical-switch application.
Rogério N. Nogueira - One of the best experts on this subject based on the ideXlab platform.
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Advances and new applications using the acousto-optic effect in optical fibers
Photonic Sensors, 2013Co-Authors: Alexandre A. P. Pohl, Roberson A Oliveira, Kevin Cook, John Canning, Ricardo E. Silva, Carlos A. F. Marques, Paulo De Tarso Neves, Rogério N. NogueiraAbstract:This work presents a short review of the current research on the acousto-optic mechanism applied to optical fibers. The role of the piezoelectric element and the acousto-optic modulator in the excitation of flexural and longitudinal acoustic modes in the frequency range up to 1.2 MHz is highlighted. A combination of the finite elements and the transfer matrix methods is used to simulate the interaction of the waves with Bragg and long period gratings. Results show a very good agreement with experimental data. Recent applications such as the writing of gratings under the acoustic excitation and a novel viscometer sensor based on the acousto-optic mechanism are discussed.
V. B. Voloshinov - One of the best experts on this subject based on the ideXlab platform.
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An Experimental Study of Ultra-Wide-Band and Ultra-Wide-Aperture Non-Collinear Acousto-Optic Diffraction in an Optically Biaxial Potassium Arsenate Titanyl Crystal
Moscow University Physics Bulletin, 2018Co-Authors: M. G. Milkov, V. B. Voloshinov, L. I. Isaenko, V. N. VedenyapinAbstract:Acousto-optic interaction in an optically biaxial crystalline medium under propagation of light close to one of the optical axes of a potassium arsenate titanyl KTiOAsO_4 crystal has been studied. The experimental dependences of the intensity of a diffracted optical beam on the angle of light incidence on an ultrasonic wave have been obtained. It has been shown that a flat cut of a wave-vector surface provides development of an ultra-wide-aperture and ultra-wide-band acousto-optic deflector to control radiation in the visible and infrared electromagnetic spectral ranges.
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Application potential of paratellurite and iodic acid crystals for Acousto-Optics in the Terahertz range
Physics of Wave Phenomena, 2017Co-Authors: D. L. Porokhovnichenko, V. B. Voloshinov, E. A. Dyakonov, G. A. Komandin, I. E. Spektor, V. D. TravkinAbstract:The possibility of applying paratellurite, iodic acid, and lithium iodate crystals in Acousto-Optics in the THz range has been investigated. The transparency windows of these crystals and their refractive indices in the THz range have been determined. The acousto-optic figures of merit of these materials are calculated for different acousto-optic interaction geometries.
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Photoelastic and acousto-optic properties of the KDP crystal with application to wide-angle acousto-optic tunable filters
Physics of Wave Phenomena, 2016Co-Authors: T. V. Yukhnevich, V. B. VoloshinovAbstract:Acousto-optic properties of the KDP crystal are analyzed with application to wide-angle acousto-optic tunable filters. The analysis is based on the measurements of the effective photoelastic constant in KDP crystals at the optical wavelengths of 405, 532.5, and 633 nm. The disagreement between the experimental and literature data is discussed.
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Acousto-optic study of the unusual cases of reflection of bulk elastic waves in a paratellurite crystal
Acoustical Physics, 2012Co-Authors: E. A. D’yakonov, V. B. Voloshinov, N. V. PolikarpovaAbstract:The propagation and reflection of bulk ultrasonic waves in a paratellurite crystal have been investigated by the acousto-optic method. Simultaneous excitation of two acoustic waves by one piezoelectric transducer has been observed in a cell of complex, specially chosen configuration. Maximally efficient conversion of the energy of a quasi-longitudinal wave into a single reflected quasi-shear wave with a walkoff angle 72° is implemented for the reflection from a free crystal boundary. The wave beam compression by a factor of 7 is observed for this reflection. A reflection (close to backward) of waves with an angle of spatial separation of the incident and reflected beams equal to 8° is also implemented. The acousto-optic figure of merit values of the medium are calculated for arbitrary propagation and polarization directions of the interacting light and ultrasonic waves. Possible applications of the effects studied in Acousto-Optics and acoustoelectronics are indicated.
