The removal speckle using a computer-generated random-phase hologram plate in green wavelength (532 nm)

2005 ◽  
Author(s):  
Sung Chul Shin
Keyword(s):  
2007 ◽  
Vol 95 ◽  
pp. 411-415
Author(s):  
T. Hauffman ◽  
J.-B. Jorcin ◽  
Y. V. Ingelgem ◽  
T. Breugelmans ◽  
E. Tourwe ◽  
...  
Keyword(s):  

2020 ◽  
pp. 3-5
Author(s):  
Y. G. Zakharenko ◽  
N. A. Kononova ◽  
V. L. Fedorin ◽  
Z. V. Fomkina ◽  
K. V. Chekirda

The results of the work to create a complex of high-precision hardware for the unit of length reproduction and transferring carried out at “D. I. Mendeleyev Institute for Metrology (VNIIM)” are represented. This complex will serve as the basis for the further development of the reference base of the Russian Federation in the field of length measurements and will allow reproduction of the unit of length at two wavelengths of 633 nm and 532 nm, as well as measurements of the wavelength of laser sources in vacuum in the range from 500 to 1050 nm.


2020 ◽  
pp. 139-143

Natural dyes were followed and prepared from a pomegranate, purple carrot, and eggplant peel. The absorbance spectra was measured in the wavelength range 300-800 nm. The linear properties measurements of the prepared natural dye freestanding films were determined include absorption coefficient (α0), extinction coefficient (κ), and linear refraction index (n). The nonlinear refractive index n2 and nonlinear absorption coefficient β2 of the natural dyes in the water solution were measured by the optical z-scan technique under a pumped solid state laser at a laser wavelength of 532 nm. The results indicated that the pomegranate dye can be promising candidates for optical limiting applications with significantly low optical limiting of 3.5 mW.


2018 ◽  
pp. 20-22
Author(s):  
D.A. Goydin ◽  
◽  
S.V. Shutova ◽  
A.P. Goydin ◽  
O.L. Fabrikantov ◽  
...  
Keyword(s):  

2014 ◽  
Vol 52 (6) ◽  
pp. 89-94
Author(s):  
N. Dumbrova ◽  
◽  
N. Molchanyuk ◽  
T. Romanova ◽  
N. Gavronskaya ◽  
...  

Author(s):  
Aarushi Shrivastava ◽  
Janki Ballabh Sharma ◽  
Sunil Dutt Purohit

Objective: In the recent multimedia technology images play an integral role in communication. Here in this paper, we propose a new color image encryption method using FWT (Fractional Wavelet transform), double random phases and Arnold transform in HSV color domain. Methods: Firstly the image is changed into the HSV domain and the encoding is done using the FWT which is the combination of the fractional Fourier transform with wavelet transform and the two random phase masks are used in the double random phase encoding. In this one inverse DWT is taken at the end in order to obtain the encrypted image. To scramble the matrices the Arnold transform is used with different iterative values. The fractional order of FRFT, the wavelet family and the iterative numbers of Arnold transform are used as various secret keys in order to enhance the level of security of the proposed method. Results: The performance of the scheme is analyzed through its PSNR and SSIM values, key space, entropy, statistical analysis which demonstrates its effectiveness and feasibility of the proposed technique. Stimulation result verifies its robustness in comparison to nearby schemes. Conclusion: This method develops the better security, enlarged and sensitive key space with improved PSNR and SSIM. FWT reflecting time frequency information adds on to its flexibility with additional variables and making it more suitable for secure transmission.


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