Chaotic time-delay signature suppression in lasers using phase-controlled dual optical feedback

TL;DR

This paper demonstrates that controlling the feedback phase in a dual optical feedback setup for semiconductor lasers significantly suppresses the time delay signature and enhances chaotic bandwidth, outperforming single feedback configurations.

Contribution

It introduces phase-controlled dual optical feedback as an effective method to suppress time delay signatures in laser chaos, with experimental validation.

Findings

Time delay signature reduced by a factor of 2

Feedback phase control is essential for suppression

Enhanced chaotic bandwidth achieved

Abstract

We experimentally study a semiconductor laser subject to two optical feedbacks in a free space setup. We show that the time delay signature, manifesting itself in the chaotic output intensity, can be better suppressed than in a laser with single feedback. We demonstrate that the control of the feedback phase is essential to suppress the time delay signature, in contrast to the one-delay case, and that the feedback phase also impacts the chaotic bandwidth. By optimizing the feedback phase the time delay signature can be reduced by a factor of 2 while maintaining a large chaotic bandwidth.