An iterative method based FLC-SLM system design for forming multiple complex structures simultaneously in 3D volume with tissue

Abstract

Complex structure formation and fast focusing of light inside or through turbid media is a challenging task due to refractive index heterogeneity, random light scattering and speckle noise formation. Here, we have proposed a weighted-mutation assisted genetic algorithm (WMA-GA) with an R-squared metric based fitness function that advances the contrast, resolution, focuses light tightly and does fast convergence for both simple and complex structure formation through the scattering media. As a compatible system with the binary WMA-GA, we have presented a fast, cost-effective, and robust iterative wavefront shaping system design with an affordable ferroelectric liquid crystal (FLC) based binary-phase spatial light modulator (SLM). The proposed wavefront shaping system design has been used to construct multiple complex hetero-structures simultaneously in 3D volume by an optimized single phase-mask. The WMA-GA and the prototype system have been validated with 120, 220, 450, and 600 grit ground glass diffusers along with 323, 588, and 852 {\mu}m thick fresh chicken tissues including fluorescence in it. We have demonstrated the robustness of the proposed method to control the photon-in and photon-out from a localized fluorescent dye embedded in the tissue. The detailed results show that the proposed class of algorithm-backed integrated system converges fast with higher contrast and advances the resolution.