scholarly journals Optical Intensity Far-Field Distribution of MEMS Micro-mirror Arrays by Fraunhofer Diffraction

2021 ◽  
Author(s):  
Bin Zhang ◽  
Yu Zhang ◽  
Guohui Yang ◽  
Chunhui Wang
Keyword(s):  
Liquid Crystal ◽  
Laser Beam ◽  
Field Distribution ◽  
Scanning Speed ◽  
Far Field ◽  
Optical Intensity ◽  
Fraunhofer Diffraction ◽  
Observation Plane ◽  
Slit Experiment

Compared with liquid crystal clad waveguide, MEMS mirror has some merits, such as high-er-transmissivity, lager-angle of scanning, faster scanning speed and so on. Furthermore, MEMS mirror arrays perform more superior than MEMS mirror when they steer laser beam, which make MEMS arrays much more suitable to be used in devising compact Lidar. Before assembling a Lidar with MEMS arrays, the optical intensity and distributions of the laser diffracted by MEMS arrays should be analyzed, but few published papers about this issue are available so far, this paper will focus on this issue about MEMS arrays. Firstly, the complex amplitudes of laser which is diffracted by 1-D and 2-D arrays are presented, respectively. Then the optical intensity and distributions on the observation plane are presented. Finally, the simulation diagrams of these distributions are shown, and the correctness of the results is indirectly verified by Young’s dou-ble-slit experiment. The results gotten in this letter are essential to design a compacted Lidar based on MEMS arrays.

Optical intensity far-field distribution of MEMS micro-mirror arrays by Fraunhofer diffraction

2021 ◽  
Vol 14 (10) ◽  
pp. 102006
Author(s):  
Bin Zhang ◽  
Yu Zhang ◽  
Guohui Yang ◽  
Chunhui Wang
Keyword(s):  
Field Distribution ◽  
Far Field ◽  
Optical Intensity ◽  
Fraunhofer Diffraction

Precision Control of Laser Beam Based on Liquid Crystal Spacial Light Modulator in Ultro-Precision Manufacturing

2014 ◽  
Vol 613 ◽  
pp. 401-407
Author(s):  
Jian Zhang ◽  
Li Ying Wu ◽  
Dong Wang
Keyword(s):  
Liquid Crystal ◽  
Laser Beam ◽  
Phase Distribution ◽  
Focal Point ◽  
Incident Beam ◽  
Far Field ◽  
Precision Manufacturing ◽  
Light Modulator ◽  
Precision Control ◽  
Distribution Shape

Laser beam precision control in ultro-precision manufacturing or other applications is to manipulate the beam pointing, intensity distribution, shape, far field patterns and so on. The method of beam control we used is different from traditional way that with mechanical inertia parts. The Liquid Crystal Spacial Light Modulator (LCSLM) is an electronic controlled, programmable diffractive device, which is able to modulate the phase of incident beam, therefore generate the objective patterns in far field. To establish the relationship between phase distribution of LCSLM and the far field objective function that represents the requirement of application, FFT and improved G-S algorithm are employed. Multi-beam focal point 3D control, beam shaping from Gaussian distribution to square and annular distribution with flat-top are discussed. They were studied in both theoretical and experimental ways. The results are evaluated by using error of root mean square and diffraction efficiency, which are less than 1% and higher than 90%, respectively.

Influence of Aberration on Far-Field Distribution of Laser Beam Emitted by Space Laser Communication System

2020 ◽  
Vol 40 (22) ◽  
pp. 2206001
Author(s):  
姜承志 Jiang Chengzhi ◽  
张文睿 Zhang Wenrui ◽  
汪波 Wang Bo ◽  
张若凡 Zhang Ruofan ◽  
朱晓程 Zhu Xiaocheng ◽  
...  
Keyword(s):  
Laser Beam ◽  
Field Distribution ◽  
Communication System ◽  
Laser Communication ◽  
Far Field

Laser Beam Modulation Freezing on a Liquid Crystal Surface

1998 ◽  
Vol 320 (1) ◽  
pp. 69-76 ◽  
Author(s):  
D. Andrienko ◽  
O. Francescangeli ◽  
E. Ouskova ◽  
F. Simoni ◽  
S. Slussarenko ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Laser Beam ◽  
Crystal Surface ◽  
Beam Modulation ◽  
Laser Beam Modulation

scholarly journals Nonlinear optics and liquid crystal light valve for laser beam control

2008 ◽  
Vol 139 ◽  
pp. 012010
Author(s):  
Jean Pierre Huignard ◽  
Arnaud Brignon ◽  
Bastien Steinhausser
Keyword(s):  
Liquid Crystal ◽  
Nonlinear Optics ◽  
Laser Beam ◽  
Beam Control ◽  
Light Valve

Study of optical parameters of two fluorinated isothiocyanato nematic liquid crystals exhibiting high birefringence

2014 ◽  
Vol 22 (1) ◽  
Author(s):  
T. Devi ◽  
B. Choudhury ◽  
A. Bhattacharjee ◽  
R. Dabrowski
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Laser Beam ◽  
Order Parameter ◽  
Refractive Indices ◽  
Optical Parameters ◽  
Optical Studies ◽  
High Birefringence ◽  
Two Samples ◽  
Direct Extrapolation

AbstractOptical studies have been carried out on two fluorinated isothiocyanato nematic liquid crystal (LC) compounds 4′-butylcyclohexyl-3, 5-difluoro-4-isothiocyanatobiphenyl and 4′-pentylcyclohexyl-3, 5-difluoro-4-isothiocynatobiphenyl. Transition temperatures of the two samples were confirmed using a polarizing microscope. The two LC compounds were found to exhibit fairly high clearing temperatures. Measurements of refractive indices of the two compounds were done by using thin prism method with He-Ne laser beam of wavelength 630 nm. Birefringence of the two LC compounds was calculated from the measured refractive indices. Both the compounds are found to display fairly high values of birefringence. Validation of a modified four-parameter model, based on Vuks equation describing the temperature dependence of refractive indices of the two liquid crystals, is also presented in this paper. The model is validated by fitting the experimentally measured values of refractive indices, birefringence and average refractive indices of the two nematic LCs with the theoretical values. In this paper, the calculation of order parameters of the LCs is presented by using two methods: direct extrapolation method based solely on the birefringence data and by using modified Vuks method based on Haller’s extrapolation. As observed from the obtained results, this procedure of calculating order parameter gives very reasonable results.

scholarly journals Pulsed UV Laser Processing of Carbosilane and Silazane Polymers

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 372 ◽  
Author(s):  
Samuel Ligon ◽  
Gurdial Blugan ◽  
Jakob Kuebler
Keyword(s):  
Laser Beam ◽  
Laser Processing ◽  
Scanning Speed ◽  
Inert Atmosphere ◽  
Laser Wavelength ◽  
Uv Laser ◽  
Glass Substrates ◽  
Polymer Precursors ◽  
Laser Systems ◽  
Pre Treatment

Freestanding SiCNO ceramic pieces with sub-mm features were produced by laser crosslinking of carbosilane and silazane polymer precursors followed by pyrolysis in inert atmosphere. Three different pulsed UV laser systems were investigated, and the influence of laser wavelength, operating power and scanning speed were all found to be important. Different photoinitiators were tested for the two lasers operating at 355 nm, while for the 266 nm laser, crosslinking occurred also without photoinitiator. Pre-treatment of glass substrates with fluorinated silanes was found to ease the release of green bodies during solvent development. Polymer crosslinking was observed with all three of the laser systems, as were bubbles, surface charring and in some cases ablation. By focusing the laser beam several millimeters above the surface of the resin, selective polymer crosslinking was observed exclusively.

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