# Suppression of coherence collapse in semiconductor Fano lasers

## TL;DR

This paper demonstrates that semiconductor Fano lasers significantly reduce or eliminate coherence collapse caused by external optical feedback, outperforming conventional lasers and enhancing stability for integrated photonics applications.

## Contribution

The study introduces a novel approach showing that semiconductor Fano lasers suppress feedback-induced instabilities, with analytical insights into the critical feedback levels involved.

## Key findings

- Fano lasers exhibit orders of magnitude better feedback stability than Fabry-Perot lasers.
- In many cases, coherence collapse is completely suppressed in Fano lasers.
- An analytical expression for the critical feedback level is derived.

## Abstract

We show that semiconductor Fano lasers strongly suppress dynamic instabilities induced by external optical feedback. A comparison with conventional Fabry-Perot lasers shows orders of magnitude improvement in feedback stability, and in many cases even total suppression of coherence collapse, which is of major importance for applications in integrated photonics. The laser dynamics are analysed using a generalisation of the Lang-Kobayashi model for semiconductor lasers with external feedback, and an analytical expression for the critical feedback level is derived.