Liquid crystal display as spatial light modulator for diffractive optical elements and the reconstruction of digital holograms

2001 ◽  
Author(s):  
Guenther K. Wernicke ◽  
Sven Krueger ◽  
Hartmut Gruber ◽  
Nazif Demoli ◽  
Matthias Duerr ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Spatial Light Modulator ◽  
Liquid Crystal Display ◽  
Diffractive Optical Elements ◽  
Light Modulator ◽  
Optical Elements ◽  
Digital Holograms

scholarly journals Liquid Crystal Spatial Light Modulator with Optimized Phase Modulation Ranges to Display Multiorder Diffractive Elements

2019 ◽  
Vol 9 (13) ◽  
pp. 2592 ◽  
Author(s):  
Elisabet Pérez-Cabré ◽  
María Sagrario Millán
Keyword(s):  
Liquid Crystal ◽  
Phase Modulation ◽  
Spatial Light Modulator ◽  
Visible Spectrum ◽  
Chromatic Aberration ◽  
Light Modulator ◽  
Optical Elements ◽  
First Order ◽  
Large Phase ◽  
Liquid Crystal On Silicon

A liquid crystal on silicon spatial light modulator (LCoS SLM) with large phase modulation has been thoroughly characterized to operate optimally with several linear phase modulation ranges (π, 2π, 3π, 4π, 6π, and 8π) for an intermediate wavelength of the visible spectrum (λG = 530 nm). For each range, the device response was also measured for two additional wavelengths at the blue and red extremes of the visible spectrum (λB = 476 nm and λR = 647 nm). Multiorder diffractive optical elements, displayed on the LCoS SLM with the appropriate phase modulation range, allowed us to deal with some widely known encoding issues of conventional first-order diffractive lenses such as undersampling and longitudinal chromatic aberration. We designed an achromatic multiorder lens and implemented it experimentally on the SLM. As a result, the residual chromatic aberration reduces to one-third that of the chromatic aberration of a conventional first-order diffractive lens.

Optical image encryption scheme with extended visual cryptography and non-mechanical ptychographic encoding

2022 ◽  
Author(s):  
Han Yu ◽  
Yong Li ◽  
Junhao Zhang ◽  
Dongyu Yang ◽  
Tianhao Ruan ◽  
...  
Keyword(s):  
Image Encryption ◽  
Spatial Light Modulator ◽  
Visual Cryptography ◽  
Optical Image ◽  
Encryption Scheme ◽  
Diffractive Optical Elements ◽  
Light Modulator ◽  
Optical Elements ◽  
Encoding Scheme ◽  
Optical Image Encryption

Abstract Non-mechanical ptychographic encoding (NPE) transforms the secret information into a series of diffractive patterns through a spatial light modulator, saving the need to fabricate the secret objects. Conventionally, the shares in extended visual cryptography (EVC) are printed on transparent sheets or fabricated with diffractive optical elements and metasurface, but these methods are expensive and disposable. To solve these problems, we proposed an optical image encryption scheme that combines EVC and NPE. In the encryption process, the secret image is decomposed into multiple shares that are digitally loaded on the spatial light modulator, and the ciphertexts are generated according to the ptychographic encoding scheme. The decryption is performed by superimposing the shares reconstructed from the ciphertexts. We present optical experiments to demonstrate the feasibility and effectiveness of the proposed method.

A Visible Near-Infrared Hadamard Transform Spectrometer Based on a Liquid Crystal Spatial Light Modulator Array: A New Approach in Spectrometry

1987 ◽  
Vol 41 (5) ◽  
pp. 727-734 ◽  
Author(s):  
D. C. Tilotta ◽  
R. M. Hammaker ◽  
W. G. Fateley
Keyword(s):  
Liquid Crystal ◽  
Spatial Light Modulator ◽  
Near Infrared ◽  
Liquid Crystal Display ◽  
Emission Spectra ◽  
Infrared Region ◽  
Hadamard Transform ◽  
Light Modulator ◽  
New Approach ◽  
Single Detector

A stationary Hadamard encodement mask has been designed from a liquid crystal display. This mask, when properly installed and positioned in a dispersive instrument, allows the selected Hadamard encoded spectral elements to be focused on a single detector. Discussion of the advantages derived by this technique is presented. Several emission spectra in the visible and near-infrared region demonstrate the usefulness of the Hadamard transform technique. This novel spectrometer can provide a no-moving-parts spectroscopy for future spectral applications.

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