Auto-optimized compensation of pixel alignment in digital optical phase conjugation system

Author(s):  
Pan Zhang ◽  
Zhan li ◽  
Lu Han ◽  
Shuaishuai Yang ◽  
Dean Liu ◽  
...  
2020 ◽  
Vol 10 (3) ◽  
pp. 875 ◽  
Author(s):  
Kai Zhang ◽  
Zhiyang Wang ◽  
Haihan Zhao ◽  
Chao Liu ◽  
Haoyun Zhang ◽  
...  

Due to the light scattering effect, it is difficult to directly achieve optical focusing and imaging in turbid media, such as milk and biological tissue. The turbidity suppression of a scattering medium and control of light through the scattering medium are important for imaging on biological tissue or biophotonics. Optical phase conjugation is a novel technology on turbidity suppression by directly creating phase conjugation light waves to form time-reversed light. In this work, we report a digital optical phase conjugation system based on off-axis holography. Compared with traditional digital optical phase conjugation methods, the off-axis holography acquires the conjugation phase using only one interference image, obviously saving photo acquisition time. Furthermore, we tested the optical phase conjugate reduction performance of this system and also achieved optical focusing through the diffuser. We also proved that the reversing of random scattering in turbid media is achievable by phase conjugation.


2020 ◽  
Vol 10 (23) ◽  
pp. 8321
Author(s):  
Pan Zhang ◽  
Zhan Li ◽  
Lu Han ◽  
Dean Liu ◽  
Jianqiang Zhu

In this paper, a reliable automatic optimized method for a digital optical phase conjugation (DOPC) system based on a multipopulation genetic algorithm (MPGA) is proposed for improving the compensation quality of DOPC. The practical implementation and compensation quality of DOPC in focusing through scattering media are greatly limited by imperfect pixel alignment, optical aberration, and mechanical error in the DOPC system. For comprehensively solving the above problems, the concept of global optimization is introduced by Zernike polynomials (Zernike modes) to characterize overall imperfections, and MPGA is used to search for the most optimal Zernike coefficient and compensate for the overall imperfections of the DOPC system. The significant optimization ability of the proposed method is verified in DOPC-related experiments for focusing through scattering media. The peak-to-background ratio (PBR) of the OPC focus increases 174 times that of the initial OPC focus. Furthermore, we evaluated the optimization results of the proposed method with a fitness function of intensity fitness and correlation coefficient fitness in MPGA. The results show that the optimized capability is excellent and more efficiently used than the correlation coefficient fitness function in the Zernike modes.


IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 44059-44068
Author(s):  
Lakshmi Narayanan Venkatasubramani ◽  
Aneesh Sobhanan ◽  
Anirudh Vijay ◽  
R. David Koilpillai ◽  
Deepa Venkitesh

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