scholarly journals The combined use of adaptive optics and nonlinear optical wavefront reversal techniques to compensate for turbulent distortions when focusing laser radiation on distant objects

2020 ◽  
Vol 44 (4) ◽  
pp. 519-532 ◽  
Author(s):  
V.P. Lukin ◽  
N.N. Botygina ◽  
P.A. Konyaev ◽  
O.V. Kulagin ◽  
I.A. Gorbunov

Approaches to constructing a mock-up of a system for focusing laser radiation on distant objects using both adaptive optics elements and nonlinear-optical wavefront reversal methods providing compensation for turbulent distortions are considered. Numerical calculations were preliminarily performed, in which the split-step method was used as a numerical method for solving a second-order partial differential wave equation for the complex amplitude of the wave field of a laser beam. This method, combined with methods of spectral-phase Fourier transforms and statistical tests, is the most effective way to obtain reliable quantitative results for solving engineering problems of atmospheric wave optics. Quantitative data are obtained on the effect of turbulent atmospheric distortions along propagation paths on the main parameters of coherent laser beams – focusing, effective average radius, and the proportion of the beam energy in its diffraction spot. The preliminary results obtained of the system mock-up performance confirm the conclusions of the theory.

2015 ◽  
Vol 41 (5) ◽  
pp. 418-421 ◽  
Author(s):  
A. S. Elshin ◽  
N. Yu. Firsova ◽  
M. A. Marchenkova ◽  
V. I. Emel’yanov ◽  
I. P. Pronin ◽  
...  

2001 ◽  
Vol 68 (12) ◽  
pp. 876 ◽  
Author(s):  
V. P. Belousov ◽  
I. M. Belousova ◽  
E. A. Gavronskaya ◽  
V. A. Grigorev ◽  
A. G. Kalintsev ◽  
...  

Author(s):  
Meider J ◽  
Messal C

Taking a tape-lift sample is one of the main practices used by indoor environmental quality investigators for detecting whether mould structures (for example, spores and hyphae) have either settled onto or colonized the surface. Despite the popularity of the method, there can be significant inconsistency in how tape lifts are collected and evaluated. The common ASTM standard D7910-14: Practice for the Collection of Fungal Material from Surfaces by Tape Lift, describes the correct way to collect a tape-lift sample. Using ASTM D7658-17: Standard Test Method for Direct Microscopy of Fungal Structures from Tape, semi-quantitative results in percentage of infested area in a scale from 0 up to 5 are available only. In case histories or for mould removal control, the total cell count is needed. This cannot be realized by the ASTM method. Therefore, an innovative method is asked to combine the quickness of taping and the precision of total cell count. Our research team developed two methods to quickly and fully quantify the tape samples. Regarding the assessment criteria, the user can decide to operate with the 3-LINE method to achieve the highest precision or use the faster 3-STEP method for even better results. Therefore, an innovative method is asked to combine the quickness of taping and the precision of total cell count. The aim of the work is to develop two strategies to quickly and comprehensive quantify the tape samples.


2019 ◽  
Vol 19 (7) ◽  
pp. 4167-4171
Author(s):  
Fatih Ungan ◽  
Huseyin Sari ◽  
Esin Kasapoglu ◽  
Unal Yesilgul ◽  
Serpil Sakiroglu ◽  
...  

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