Algorithm For Computation Of Large Size Fast Fourier Transforms In Computer-Generated Holograms By Interlaced Sampling

1989 ◽  
Vol 28 (6) ◽  
Author(s):  
Hamid Farhoosh ◽  
Yeshaiahu Fainman ◽  
Sing H. Lee
Keyword(s):  
Fourier Transforms ◽  
Fast Fourier Transforms ◽  
Large Size ◽  
Computer Generated Holograms ◽  
Interlaced Sampling

An Algorithm For Computation Of Large Size FFTs In Computer Generated Holograms By Interlaced Sampling

1988 ◽  
Author(s):  
Harnid Farhoosh ◽  
Reiner Eschbach ◽  
Yashaiahu Fainman ◽  
Sing H. Lee
Keyword(s):  
Large Size ◽  
Computer Generated Holograms ◽  
Interlaced Sampling

scholarly journals Optical Encryption Based on Computer Generated Holograms in Photopolymer

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1358
Author(s):  
Taihui Wu ◽  
Jianshe Ma ◽  
Chengchen Wang ◽  
Haibei Wang ◽  
Liangcai Cao ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Angular Spectrum ◽  
Quick Response ◽  
Response Code ◽  
Optical Encryption ◽  
Large Size ◽  
Quick Response Code ◽  
Computer Generated Holograms ◽  
Encryption Method

An optical encryption method based on computer generated holograms printing of photopolymer is presented. Fraunhofer diffraction is performed based on the Gerchberg-Saxton algorithm, and a hologram of the Advanced Encryption Standard encrypted Quick Response code is generated to record the ciphertext. The holograms of the key and the three-dimensional image are generated by the angular spectrum diffraction algorithm. The experimental results show that large-size encrypted Quick Response (QR) code and miniature keys can be printed in photopolymers, which has good application prospects in optical encryption. This method has the advantages of high-density storage, high speed, large fault tolerance, and anti-peeping.

Data Acquisition and Processing of Weak Low-Frequency Magnetic Signals

2011 ◽  
Vol 65 ◽  
pp. 299-302 ◽  
Author(s):  
Shou Qiang Men ◽  
Christian Resagk
Keyword(s):  
Magnetic Field ◽  
Data Acquisition ◽  
Fourier Transforms ◽  
Low Frequency ◽  
Fast Fourier Transforms ◽  
Two Dimensional ◽  
Calibration System ◽  
Magnetic Field Sensors ◽  
Data Acquisition And Processing

A simple calibration system for magnetic field sensors was designed, and experiments were carried out to calibrate two-dimensional fluxgate sensors and a sensor ring composed of eight fluxgate sensors. Fast Fourier Transforms and trapezoidal numerical integrals were applied to deal with the raw signals. It is found that it is not suitable to apply fast Fourier Transforms only to deal with signals with several peaks close to each other, but trapezoidal numerical integrals should also be used in combination with the FFT method.

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