Solving the logarithmic Monge-Ampère equation with a RK4-algorithm for beam shaping purposes of femtosecond laser beams with spatial light modulators

2018 ◽  
Author(s):  
Steffan Weissmantel ◽  
Alexander Kratsch ◽  
Markus Olbrich ◽  
Alexander Horn
Keyword(s):  
Femtosecond Laser ◽  
Beam Shaping ◽  
Laser Beams ◽  
Spatial Light Modulators ◽  
Light Modulators ◽  
Monge Ampere

scholarly journals Holographic Display System to Suppress Speckle Noise Based on Beam Shaping

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 204
Author(s):  
Di Wang ◽  
Yi-Wei Zheng ◽  
Nan-Nan Li ◽  
Qiong-Hua Wang
Keyword(s):  
Optical Element ◽  
Speckle Noise ◽  
Beam Shaping ◽  
Diffractive Optical Element ◽  
The Other ◽  
Spatial Light Modulators ◽  
Viewing Angle ◽  
Display System ◽  
Holographic Display ◽  
Light Modulators

In this paper, a holographic system to suppress the speckle noise is proposed. Two spatial light modulators (SLMs) are used in the system, one of which is used for beam shaping, and the other is used for reproducing the image. By calculating the effective viewing angle of the reconstructed image, the effective hologram and the effective region of the SLM are calculated accordingly. Then, the size of the diffractive optical element (DOE) is calculated accordingly. The dynamic DOEs and effective hologram are loaded on the effective regions of the two SLMs, respectively, while the wasted areas of the two SLMs are performed with zero-padded operations. When the laser passes through the first SLM, the light can be modulated by the effective DOEs. When the modulated beam illuminates the second SLM which is loaded with the effective hologram, the image is reconstructed with better quality and lower speckle noise. Moreover, the calculation time of the hologram is reduced. Experiments indicate the validity of the proposed system.

scholarly journals Progress in fabrication of waveguide spatial light modulators via femtosecond laser micromachining

2017 ◽  
Author(s):  
Nickolaos Savidis ◽  
Sundeep Jolly ◽  
Bianca Datta ◽  
Michael Moebius ◽  
Thrasyvoulos Karydis ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Micromachining ◽  
Spatial Light Modulators ◽  
Light Modulators ◽  
Femtosecond Laser Micromachining

scholarly journals High damage threshold liquid crystal binary mask for laser beam shaping

2019 ◽  
Vol 7 ◽  
Author(s):  
Gang Xia ◽  
Wei Fan ◽  
Dajie Huang ◽  
He Cheng ◽  
Jiangtao Guo ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Laser Beam ◽  
Metal Layer ◽  
Damage Threshold ◽  
Beam Shaping ◽  
Spatial Light Modulators ◽  
Binary Mask ◽  
Light Modulators ◽  
New Type ◽  
Multiple Shot

In order to improve the damage threshold and enlarge the aperture of a laser beam shaper, photolithographic patterning technology is adopted to design a new type of liquid crystal binary mask. The inherent conductive metal layer of commercial liquid crystal electro-optical spatial light modulators is replaced by azobenzene-based photoalignment layers patterned by noncontact photolithography. Using the azobenzene-based photoalignment layer, a liquid crystal binary mask for beam shaping is fabricated. In addition, the shaping ability, damage threshold, write/erase flexibility and stability of the liquid crystal binary mask are tested. Using a 1 Hz near-IR (1064 nm) laser, the multiple-shot nanosecond damage threshold of the liquid crystal mask is measured to be higher than $15~\text{J}/\text{cm}^{2}$. The damage threshold of the azobenzene-based photoalignment layer is higher than $50~\text{J}/\text{cm}^{2}$ under the same testing conditions.

Beam shaping using liquid crystal-on-silicon spatial light modulators for laser ultrasound generation

2014 ◽  
Vol 53 (4) ◽  
pp. 044110 ◽  
Author(s):  
Michael Kalms ◽  
Sandra Hellmers ◽  
Philipp Huke ◽  
Ralf B. Bergmann
Keyword(s):  
Liquid Crystal ◽  
Beam Shaping ◽  
Spatial Light Modulators ◽  
Laser Ultrasound ◽  
Light Modulators ◽  
Liquid Crystal On Silicon

scholarly journals High-quality micropattern printing by interlacing-pattern holographic femtosecond pulses

Nanophotonics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 2895-2904 ◽  
Author(s):  
Zhipeng Wang ◽  
Xiaowei Li ◽  
Lan Jiang ◽  
Bohong Li ◽  
Qunshuo Wei ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
High Efficiency ◽  
Speckle Noise ◽  
Device Fabrication ◽  
Spatial Light Modulators ◽  
Direct Writing ◽  
Optical Fields ◽  
High Quality ◽  
Target Pattern ◽  
Light Modulators

AbstractTo improve the efficiency of femtosecond laser direct writing, holographic femtosecond laser patterning using spatial light modulators has been widely used for the processing of micro/nanopatterns. However, the speckle noise of modulated optical fields severely limits the quality of fabricated patterns. We present a simple and effective method which involves interlacing a target pattern into a series of target subpatterns that consist of spaced spots to solve this problem. The separation of spots weakens the random interference between adjacent spots of optical fields, so the speckle noise reduces effectively, which improves the uniformity of the modulated optical fields and makes the fabricated patterns with high quality. With optimal interlacing numbers, complex micropattern arrays containing curved edges and sophisticated structures can be fabricated with superior quality and high efficiency. Binary holograms with improved optical characterization are realized by using the interlacing-pattern method, revealing the extensive potential of this method in micropattern processing and functional device fabrication with high quality and efficiency.

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