Diffractive optical elements displayed on a ferroelectric gray-scale spatial light modulator

2002 ◽  
Author(s):  
Laurent Bigué ◽  
Pierre Ambs
Keyword(s):  
Spatial Light Modulator ◽  
Diffractive Optical Elements ◽  
Gray Scale ◽  
Light Modulator ◽  
Optical Elements

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.

scholarly journals Complex Diffractive Optical Elements Stored in Photopolymers

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1920 ◽  
Author(s):  
Roberto Fernández ◽  
Sergi Gallego ◽  
Andrés Márquez ◽  
Cristian Neipp ◽  
Eva Calzado ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Diffusion Model ◽  
Spatial Light Modulator ◽  
Diffractive Optical Elements ◽  
Light Modulator ◽  
Optical Elements ◽  
New Generation

We study the recording of complex diffractive elements, such as achromatic lenses, fork gratings or axicons. Using a 3-D diffusion model, previously validated, we are able to predict the behavior of photopolymer during recording. The experimental recording of these complex elements is possible thanks to a new generation spatial light modulator capable of generating periodic and aperiodic profiles. Both experimental and theoretical are analyzed and compared. The results show not only the good response of theoretical model to predict the behavior of the materials, but also the viability of photopolymers to store these kind of elements.

Pseudo-Color Coded Optical System Based on the Spatial Light Modulator and Charge-Coupled Device

2012 ◽  
Author(s):  
S. N. Zhao ◽  
H. Chang ◽  
J. Wei ◽  
Z. Wei
Keyword(s):  
Real Time ◽  
Optical System ◽  
Spatial Light Modulator ◽  
Processing System ◽  
Optical Processing ◽  
Gray Scale ◽  
Light Modulator ◽  
Time Modulation ◽  
Gray Scale Image ◽  
Pseudo Color

A new pseudo-color coded optical system based on the liquid crystal spatial light modulator (LC-SLM) and a digital camera (CCD) is proposed. The SLM is used to replace the holographic grating with gray-scale image information, a gray-scale image in real-time modulation methods is proposed by synthesizing phase hologram and Ronchi grating, combined with the 4f coherent optical processing system and spatial filtering. For the high resolution gray image processed with existing digital pseudo-color method, the color sensitivity is low, algorithm is very complex. For traditional optical pseudo-color method, the gray scale image needs chemical pretreatment. The process is complex and time-consuming, and the real-time modulation could not be achieved. Our new method has enhanced the flexibility and adaptability of the optical pseudo-color, and give full play to the high sensitivity, high-capacity, rich colors and other features of the optical processing mode. At the same time, it overcomes the disadvantages of pure optical system which could not perform real-time processing. Therefore, it can be widely used in the field of remote sensing, biomedical, environmental monitoring, public security and criminal investigation, etc.

Utilization of a liquid crystal spatial light modulator in a gray scale detour phase method for Fourier holograms

2012 ◽  
Vol 51 (32) ◽  
pp. 7877 ◽  
Author(s):  
Ghaith Makey ◽  
Moustafa Sayem El-Daher ◽  
Kanj Al-Shufi
Keyword(s):  
Liquid Crystal ◽  
Spatial Light Modulator ◽  
Phase Method ◽  
Gray Scale ◽  
Light Modulator
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