Iterative pixelwise approach applied to computer-generated holograms and diffractive optical elements

2017 ◽  
Vol 57 (1) ◽  
pp. A189 ◽  
Author(s):  
Wei-Feng Hsu ◽  
Shih-Chih Lin
Keyword(s):  
Diffractive Optical Elements ◽  
Optical Elements ◽  
Computer Generated Holograms

Laser interference ablation by ultrashort UV laser pulses via diffractive beam management

2020 ◽  
Vol 9 (1-2) ◽  
pp. 41-52 ◽  
Author(s):  
Jan-Hendrik Klein-Wiele ◽  
Andreas Blumenstein ◽  
Peter Simon ◽  
Jürgen Ihlemann
Keyword(s):  
Laser Pulses ◽  
Diffractive Optical Elements ◽  
Uv Laser ◽  
Laser Interference ◽  
Periodic Patterns ◽  
Optical Elements ◽  
Periodic Surface ◽  
Coherent Beams ◽  
Surface Patterns ◽  
Computer Generated Holograms

AbstractThe fabrication of periodic surface patterns on various materials by ultrashort ultraviolet (UV) laser pulses is reviewed. Laser interference ablation using two or more coherent beams leads to deterministic, strictly periodic patterns. The generation of the interfering beams is accomplished by diffractive optical elements like gratings, grating systems or computer-generated holograms. The recombination of the diffracted beams is performed by optical imaging or diffractive beam management. Ultrashort UV pulses are especially suited for generating micron- to submicron-sized deterministic periodic patterns on metals and semiconductors.

scholarly journals Frequency Division Multiplexing of Terahertz Waves Realized by Diffractive Optical Elements

2021 ◽  
Vol 11 (14) ◽  
pp. 6246
Author(s):  
Paweł Komorowski ◽  
Patrycja Czerwińska ◽  
Mateusz Kaluza ◽  
Mateusz Surma ◽  
Przemysław Zagrajek ◽  
...  
Keyword(s):  
Frequency Division Multiplexing ◽  
Diffractive Optical Elements ◽  
Frequency Division ◽  
Terahertz Waves ◽  
Optical Elements ◽  
Telecommunication Systems ◽  
Wide Range ◽  
The Future ◽  
Wireless Telecommunication ◽  
Finite Distance

Recently, one of the most commonly discussed applications of terahertz radiation is wireless telecommunication. It is believed that the future 6G systems will utilize this frequency range. Although the exact technology of future telecommunication systems is not yet known, it is certain that methods for increasing their bandwidth should be investigated in advance. In this paper, we present the diffractive optical elements for the frequency division multiplexing of terahertz waves. The structures have been designed as a combination of a binary phase grating and a converging diffractive lens. The grating allows for differentiating the frequencies, while the lens assures separation and focusing at the finite distance. Designed structures have been manufactured from polyamide PA12 using the SLS 3D printer and verified experimentally. Simulations and experimental results are shown for different focal lengths. Moreover, parallel data transmission is shown for two channels of different carrier frequencies propagating in the same optical path. The designed structure allowed for detecting both signals independently without observable crosstalk. The proposed diffractive elements can work in a wide range of terahertz and sub-terahertz frequencies, depending on the design assumptions. Therefore, they can be considered as an appealing solution, regardless of the band finally used by the future telecommunication systems.

scholarly journals Nanooptical elements for visual verification

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Goncharsky ◽  
Anton Goncharsky ◽  
Dmitry Melnik ◽  
Svyatoslav Durlevich
Keyword(s):  
Electron Beam ◽  
Electron Beam Lithography ◽  
Mass Production ◽  
Optical Element ◽  
Visual Image ◽  
Zero Order ◽  
Diffractive Optical Elements ◽  
Optical Elements ◽  
Standard Equipment ◽  
Diffractive Element

AbstractThis paper focuses on the development of flat diffractive optical elements (DOEs) for protecting banknotes, documents, plastic cards, and securities against counterfeiting. A DOE is a flat diffractive element whose microrelief, when illuminated by white light, forms a visual image consisting of several symbols (digits or letters), which move across the optical element when tilted. The images formed by these elements are asymmetric with respect to the zero order. To form these images, the microrelief of a DOE must itself be asymmetric. The microrelief has a depth of ~ 0.3 microns and is shaped with an accuracy of ~ 10–15 nm using electron-beam lithography. The DOEs developed in this work are securely protected against counterfeiting and can be replicated hundreds of millions of times using standard equipment meant for the mass production of relief holograms.

scholarly journals Mobile snapshot hyperspectral imaging device for skin evaluation using diffractive optical elements

2021 ◽  
Author(s):  
Christian Kern ◽  
Uwe Speck ◽  
Rainer Riesenberg ◽  
Carina Reble ◽  
Georg Khazaka ◽  
...  
Keyword(s):  
Hyperspectral Imaging ◽  
Diffractive Optical Elements ◽  
Optical Elements ◽  
Imaging Device

An electro-opto-mechanical device to make diffractive optical elements

2011 ◽  
Author(s):  
Jorge Castro-Ramos ◽  
Gabriel Gordiano-Alvarado ◽  
Carlos M. Ortiz-Lima ◽  
M. Antonio De-Jesus-Ortiz ◽  
Sergio Vazquez-Montiel ◽  
...  
Keyword(s):  
Diffractive Optical Elements ◽  
Mechanical Device ◽  
Optical Elements

scholarly journals Generation of diffractive optical elements onto photopolymer using liquid crystal on silicon displays

2017 ◽  
Author(s):  
Roberto Fernandez ◽  
Sergi Gallego ◽  
Francisco J. Martinez ◽  
Andres Marquez ◽  
Inmaculada Pascual ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Diffractive Optical Elements ◽  
Optical Elements ◽  
Liquid Crystal On Silicon
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