Discussion on phase ambiguity and multiple beam generation in coherent beam combining system

TL;DR

This paper analyzes phase ambiguity in coherent beam combining systems with centrosymmetric arrays, providing a theoretical solution without extra optical devices and proposing a two-stage algorithm for bi-beam generation.

Contribution

It offers the first comprehensive theoretical analysis of phase ambiguity solutions and introduces a novel method and algorithm for phase ambiguity resolution and bi-beam generation.

Findings

Identified all solutions to phase ambiguity in the system

Proposed a no-extra-device method to solve phase ambiguity

Designed a two-stage algorithm for bi-beam generation

Abstract

There exists the phase ambiguity problem in the coherent beam combining (CBC) system with centrosymmetric arrays, which means that multiple different piston aberrations may generate the same far-field image. This will cause that the far-field image can not correctly reflect the phase information, resulting in the performance degradation of image-based intelligent algorithms. In this paper, we make a theoretical analysis on phase ambiguity. To the best of our knowledge, we give the number and descriptions of all solutions of the phase ambiguity problem in above system for the first time. A method to solve phase ambiguity is proposed, which requires no additional optical devices. We designed simulations to verify our conclusions and methods. We believe that our work solves the phase ambiguity problem in theory and is conducive to improving the performance of image-based algorithms. In addition, we designed a two-stage algorithm to generate Bi-beam, which have valuables application in laser propagation.