Effect of experimental parameters on optimal reflection of light from opaque media

TL;DR

This study investigates how various experimental parameters influence the optimization of reflected light from opaque media, revealing similarities to transmissive setups and hints of new physical mechanisms beyond existing theories.

Contribution

It systematically analyzes the impact of experimental parameters on reflection optimization and suggests potential new physics beyond current models.

Findings

Experimental parameters affect reflection enhancement similarly to transmission cases.

Genetic algorithm-based optimization shows different functional dependencies.

Evidence suggests enhancements exceed predictions by random matrix theory.

Abstract

Previously we considered the effect of experimental parameters on optimized transmission through opaque media using spatial light modulator (SLM)-based wavefront shaping. In this study we consider the opposite geometry, in which we optimize reflection from an opaque surface such that the backscattered light is focused onto a spot on an imaging detector. By systematically varying different experimental parameters (genetic algorithm iterations, bin size, SLM active area, target area, spot size, and sample angle with respect to the optical axis) and optimizing the reflected light we determine how each parameter affects the intensity enhancement. We find that the effects of the experimental parameters on the enhancement are similar to those measured for a transmissive geometry, but with the exact functional forms changed due to the different geometry and the use of a genetic algorithm instead of an iterative algorithm. Additionally, we find preliminary evidence of greater enhancements than predicted by random matrix theory, suggesting a possibly new physical mechanism to be investigated in future work.