Random scattering and alternating projection optimization for active phase control of a laser beam array

TL;DR

This paper introduces a novel method combining random scattering and alternating projection optimization to rapidly and efficiently control the phase of a laser beam array through scattering media, enabling precise wavefront shaping.

Contribution

It presents an innovative optimization approach that achieves fast phase locking in laser arrays using scattering media, improving upon existing methods.

Findings

Fast convergence to desired wavefronts within few iterations

Effective phase control through scattering media

Enhanced laser beam array stability and precision

Abstract

A fraction of a laser beam array, whose unknown phase relationships must be set to prescribed values, is launched into a scattering media with random transmission. The resulting output speckle pattern is sampled by an array of photodiodes measuring the local light intensity. The data feed an innovative optimization process which controls a phase modulator array. Few iterations of the opto-numeric loop lead to efficient and fast phase locking on any desired wavefront.