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Optical imaging through scattering media is an important challenge in a variety of fields ranging from microscopy to autonomous vehicles. While advanced wavefront shaping techniques have offered significant breakthroughs in the past decade,…

Optics · Physics 2023-05-23 Omri Haim , Jeremy Boger-Lombard , Ori Katz

We demonstrate optical trapping and manipulation of defects and transparent microspheres in nematic liquid crystals (LCs). The three-dimensional director fields and positions of the particles are visualized using the Fluorescence Confocal…

We propose and experimentally demonstrate femtosecond direct laser writing with Bessel beams for the fabrication of photonic crystals with spatial filtering functionality. Such filters are mechanically stable, of small (of order of…

Applied Physics · Physics 2019-10-23 Darius Gailevičius , Vytautas Purlys , Kestutis Staliunas

Emission features formed through Raman scattering with atomic hydrogen provide unique and crucial information to probe the distribution and kinematics of a thick neutral region illuminated by a strong far UV emission source. We introduce a…

Solar and Stellar Astrophysics · Physics 2021-01-13 Seok-Jun Chang , Hee-Won Lee

The random lasing (RL) emission of dyed vesicular polymeric films in diffusive regime of light propagation was investigated under helium temperature. It represents itself the coupling effect of stimulated emission and stimulated Raman…

Optics · Physics 2010-08-27 V. P. Yashchuk , E. A. Tikhonov , O. A. Prygodiuk

Stimulated Raman scattering (SRS) microscopy allows for high-speed label-free chemical imaging of biomedical systems. The imaging sensitivity of SRS microscopy is limited to ~10 mM for endogenous biomolecules. Electronic pre-resonant SRS…

Raman sensing and Raman microscopy are amongst the most specific optical technologies to identify the chemical compounds of unknown samples, and to enable label-free biomedical imaging with molecular contrast. However, the high cost and…

Snapshot multi-dimensional imaging offers a promising alternative to traditional low-dimensional imaging techniques by enabling the simultaneous capture of spatial, spectral, polarization, and other information in a single shot for improved…

We propose to use high numerical aperture single mode optical fibers like photonic crystal fiber for lensless in-line holographic microscopy. Highly divergent beam helps to overcome the spatial sampling limitation of the image sensor. In…

Optics · Physics 2020-07-01 Sanjeev Kumar , Manjunatha Mahadevappa , Pranab K. Dutta

We study photopolymerization in a low-molecular weight liquid crystal with non-uniform director gradients. Phase separation results in spatially non-uniform distribution of polymer density controlled by the distorted nematic matrix.…

Soft Condensed Matter · Physics 2007-05-23 D. Voloschenko , O. P. Pishnyak , S. V. Shiyanovskii , O. D. Lavrentovich

An approach to significantly enhance spontaneous Raman sensitivity through the formation of a thin film via thermophoresis along with evaporation at the facet of a Hollow-Core Photonic Crystal Fiber is reported for the first time.…

Optics · Physics 2021-12-30 Basil G. Eleftheriades , Emily E. Storey , Amr S. Helmy

The evolution versus pump power of the spectrum of a singly resonant optical parametric oscillator based on an MgO-doped periodically poled stoichiometric lithium tantalate crystal is observed. The onset of cascade Raman lasing due to…

Optics · Physics 2015-05-13 T-H. My , O. Robin , O. Mhibik , C. Drag , F. Bretenaker

Optical imaging through scattering media is a fundamental challenge in many applications. Recently, substantial breakthroughs such as imaging through biological tissues and looking around corners have been obtained by the use of…

Optics · Physics 2020-07-09 Tomer Yeminy , Ori Katz

Using the shifted-excitation Raman difference spectroscopy technique and an optical fibre featuring a negative curvature excitation core and a coaxial ring of high numerical aperture collection cores, we have developed a portable,…

We demonstrate low-frequency interferometric impulsive stimulated Raman scattering (ISRS) imaging with high robustness to distortions by optical scattering. ISRS is a pump-probe coherent Raman spectroscopy that can capture Raman vibrational…

Using femtosecond laser machining, we have fabricated photonic bandgap materials that influence propagation of phonon-polaritons in ferroelectric crystals. Broadband polaritons were generated with impulsive stimulated Raman scattering…

Optics · Physics 2007-05-23 David W. Ward , Eric R. Statz , Thomas Feurer , Keith A. Nelson

We investigate for the first time the enhancement of the stimulated Raman scattering in slow-light Silicon-on-Insulator (SOI) photonic crystal line defect waveguides. By applying the Bloch-Floquet formalism to the guided modes in a planar…

Optics · Physics 2010-04-12 J. F. McMillan , X. Yang , N. C. Panoiu , R. M. Osgood , C. W. Wong

A standing-wave control field applied to a three-level atomic medium in a planar hollow-core photonic crystal waveguide creates periodic variations of linear and nonlinear refractive indexes of the medium. This property can be used for…

Optics · Physics 2015-05-18 Chao Hang , V. V. Konotop

The control over light propagation and localization in photonic crystals offers wide applications from sensing and on-chip routing to lasing and quantum light-matter interfaces. While in electronic crystals magnetic fields can be used to…

Optics · Physics 2023-06-07 René Barczyk , L. Kuipers , Ewold Verhagen

Composition-spread La1-xSrxMnO3 thin films were prepared by pulsed laser deposition technique from LaMnO3 and SrMnO3 targets. The films were epitaxial with a continuous variation of the out of plane lattice parameter along the direction of…

Materials Science · Physics 2007-05-23 A. Venimadhav , K. A. Yates , M. G. Blamire