Temporal pattern generation with tunable repetition rate using semiconductor laser periodic dynamics

TL;DR

This paper demonstrates a semiconductor laser system that generates stable, tunable, and diverse repetitive temporal patterns with potential applications in reservoir computing, achieved through optical feedback and harmonic filtering.

Contribution

It introduces a simple long-cavity semiconductor laser setup that produces stable, tunable, and diverse periodic waveforms suitable for physical waveform generation in computing architectures.

Findings

Repetition rate tunable from 3.28 to 4.21 GHz.

Stable limit cycle dynamics with multiple harmonics.

High intra-pattern diversity achieved via harmonic filtering.

Abstract

In this work, a long-cavity semiconductor laser subject to optical feedback is exploited to generate repetitive temporal patterns with enhanced intra-pattern sample diversity. Stable limit cycle dynamics characterized by multiple frequency harmonics are experimentally demonstrated by considering a 2 m external cavity with appropriate optical feedback conditions. This simple configuration can enable stable and continuous generation of periodic waveforms with a tunable repetition rate ranging from 3.28 to 4.21 GHz. Distinct, highly consistent temporal patterns are obtained by applying high-pass filtering to adjust the relative power of the harmonics. The resulting system operates as a physical waveform generator capable of producing diverse and repeatable signal patterns, making it well-suited for use in the masking stage of time delay reservoir computing architectures.