Binary phase oscillation of two mutually coupled semiconductor lasers

TL;DR

This paper demonstrates a laser network mimicking a two-site Ising model, showing phase locking behaviors that emulate ferromagnetic and antiferromagnetic orders, with potential applications in optical computing.

Contribution

It introduces a novel laser network implementing an Ising model with phase-locked states, revealing new dynamics in coupled semiconductor lasers.

Findings

Observation of ferromagnetic and antiferromagnetic phase locking.

Phase difference locked to 0 or p despite continuous modulation.

Automatic frequency selection for in-phase or out-of-phase states.

Abstract

A two-site Ising model is implemented as an injection-locked laser network consisting of a single master laser and two mutually coupled slave lasers. We observed ferromagnetic and antiferromagnetic orders in the in-phase and out-of-phase couplings between the two slave lasers. Their phase difference is locked to either 0 or p even if the coupling path is continuously modulated. The system automatically selects the oscillation frequency to satisfy the in-phase or out-of-phase coupling condition, when the mutual coupling dominates over the injection-locking by the master laser.