Photon statistics and bunching of a chaotic semiconductor laser

TL;DR

This paper explores the photon statistics and bunching behavior of a chaotic semiconductor laser with external feedback, revealing how photon distribution and coherence change with laser parameters, and demonstrating potential for randomness extraction.

Contribution

It provides a combined experimental and theoretical analysis of photon bunching and statistics in chaotic semiconductor lasers, highlighting new insights into their emission properties.

Findings

Photon number distribution transitions from Bose-Einstein to Poisson with increasing mean photon number.

Photon bunching is observed under various conditions, indicating high randomness.

Chaotic dynamics are confirmed through high-speed detection, aligning with theoretical predictions.

Abstract

The photon statistics and bunching of a semiconductor laser with external optical feedback are investigated experimentally and theoretically. In a chaotic regime, the photon number distribution is measured and undergoes a transition from Bose-Einstein distribution to Poisson distribution with increasing the mean photon number. The second order degree of coherence decreases gradually from 2 to 1. Based on Hanbury Brown-Twiss scheme, pronounced photon bunching is observed experimentally for various injection currents and feedback strengths, which indicates the randomness of the associated emission light. Near-threshold injection currents and strong feedback strengths modify exactly the laser performance to be more bunched. The macroscopic chaotic dynamics is confirmed simultaneously by high-speed analog detection. The theoretical results qualitatively agree with the experimental results. It is potentially useful to extract randomness and achieve desired entropy source for random number generator and imaging science by quantifying the control parameters.