A5049652484- Orbital Angular Momentum in Optics
- Optical Polarization and Ellipsometry
- Liquid Crystal Research Advancements
- Near-Field Optical Microscopy
- Advanced Optical Imaging Technologies
- Microfluidic and Bio-sensing Technologies
- Photonic and Optical Devices
- Advanced optical system design
- Optical Imaging and Spectroscopy Techniques
- Advanced Fluorescence Microscopy Techniques
- Plant Reproductive Biology
- Digital Holography and Microscopy
- Optical and Acousto-Optic Technologies
- Adaptive optics and wavefront sensing
- Laser-Matter Interactions and Applications
- Electrohydrodynamics and Fluid Dynamics
- Semiconductor Lasers and Optical Devices
- Laser Design and Applications
- Photoacoustic and Ultrasonic Imaging
- Plant and animal studies
- Surface Roughness and Optical Measurements
- Ophthalmology and Visual Impairment Studies
- Laser Material Processing Techniques
- Advanced Scientific Research Methods
- Optical Coherence Tomography Applications
P.N. Lebedev Physical Institute of the Russian Academy of Sciences
2015-2024
Russian Academy of Sciences
1999-2021
Samara National Research University
2014-2018
Samara Federal Research Scientific Center
2016
Astrakhan State Technical University
2014
Coherent (United States)
2006
A theoretical model for a modal liquid-crystal focusing device is developed. The solutions to the system of equations are investigated in approximation small parameter. necessary relations between control harmonic potentials implementing phase delay profile form circular truncated cone with controlled position base centre and an elliptical fixed directions major axes ellipse (which parallel aperture edges) found.
We study both experimentally and theoretically modulation of light in a planar aligned deformed-helix ferroelectric liquid crystal (DHFLC) cell with subwavelength helix pitch, which is also known as short-pitch DHFLC. In our experiments, the azimuthal angle in-plane optical axis electrically controlled parts principal refractive indices are measured function voltage applied across cell. Theoretical results giving effective tensor DHFLC expressed terms smectic tilt (FLC) used to fit...
The characteristics of a modal liquid-crystal focusing device are experimentally investigated in different control regimes. Phase delay distributions the form circular truncated cone with controlled position base centre obtained. Focusing to round spot focal point aperture area is implemented for operation regime small parameter.
Abstract The formation of phase holograms by the modulation superposition method for producing a set vortex laser beams is presented. Produced are considered to be used in scheme optical tweezers trapping and manipulation ensembles latex microspheres. Applying regarded synthesize adding harmonic functions with specific parameters. possibility independent control position produced their orbital angular momentum experimentally demonstrated, being good agreement theoretical analysis. use...
Results are presented of the properties a liquid crystal wavefront corrector for adaptive optics. The device is controlled using modal addressing in which case behaves more like continuous facesheet deformable mirror than segmented one. Furthermore, width and shape influence functions electrically controllable. We describe construction device, optical properties, we show experimental results low order aberration generation.
Microobject manipulation with a laser is investigated. The functional capabilities of the manipulators can be significantly enhanced using beams predetermined distributions intensity and angular momentum. Beams nonzero momentum are generated phase amplitude-phase masks. Such make it possible to rotate weakly absorbing particles move them along given trajectory. Experimental results on microobject motion various trajectories (circle, triangle contour, self-intersecting curve, Archimedes...
Spherical and cylindrical adaptive liquid-crystal lenses are proposed. The modal principle of control the distribution refractive index over aperture is used in these lenses. This achieved by introducing an additional high-resistance electrode placing low-resistance contacts at periphery this electrode. A theory developed physical processes occuring resultant distributed resistive — capacitative system. calculated results make it possible particular to optimise operation
A solution to a general problem for 4-channel liquid crystal (LC) modulator (LC focusing device) of the formation specified-equipotential-line voltage distribution and on its movement along aperture is presented. The modulator's capabilities control light fields in form circles, line segments ellipses an arbitrary orientation are demonstrated numerically experimentally.
The capabilities and specific features of the formation dynamic control so-called contour optical traps using a four-channel liquid crystal modulator are studied theoretically experimentally. Circular, elliptical C-shaped formed. Trapping confinement absorbing micro-objects by formed demonstrated.
A novel liquid crystal (LC) wavefront corrector with smooth modal influence functions is proposed and realized.The device consists of a thin layer planar aligned nematic LC sandwiched between glass plate conductive electrode made ceramic material very high dielectric constant.Control electrodes are positioned on the back side plate, opposite to LC.The character response determined by spreading electric field in plate.The implemented operating reflective (mirror) mode; however, similar...
The objective of this work is to assess characteristics and possible applications an adjustable focusing device based on two crossed substrates for modal cylindrical lenses. theoretical model the presented relations control potentials are obtained case a quasi-cylindrical lens. An experimental study properties carried out. experiment performed focus light into line segment with controllable orientation.
The presented here technique is developed for in vitro estimation of the influence external conditions on deformation ability human red blood cells. method based use single-beam laser trap capturing erythrocytes fixed to bottom liquid cell by adhesion force. approach suitable evaluation properties individual cells as well real-time acquisition data ensemble large enough subsequent statistical analysis. It shown that both a change saline solution concentration and presence certain stabilizing...
The results of the experimental work aimed at a functional enhancement existing laser tweezers system by introducing pixel-addressable liquid-crystal spatial light modulator (Holoeye HEO-1080P) are presented. use allows us to generate fields complicated structure including ones with vortex component and control objects positions in real time. special software is developed form an array optical traps number elements up thirty two capability individual or subgroup control. method separation...
Experiments on the dynamic control of two-dimensional optical trap spatial structure and manipulation micron-sized dielectric particles are performed with a four-channel liquid crystal modulator. Tweezers this device can execute trapping single particle its subsequent relocation along square trajectory. Also, when shaped as line segment, capture several rotate them. Therefore, it is experimentally proven that for certain tasks be compact technologically simple alternative to available...
A description is given of a numerical method for solving the equation liquid-crystal lens. An analysis made results search optimal parameters control voltage. experimental system calibration modal lenses considered. The operation this based on real-time interferograms. are reported demonstrations use adaptive in incoherent-light imaging and systems laser radiation focusing.
The application of the differential backscattering method and fluorescent analysis wood cultures for determination ecological quality different megapolis areas are investigated. correlation leaves optical characteristics with data chemical pigments concentration is shown on basis year statistical results spectral observation. It experimentally found that allows to identify their level.