Visualizing the Phase-Space Dynamics of an External Cavity Semiconductor Laser

TL;DR

This paper presents a phase-space visualization method for an external-cavity semiconductor laser, revealing complex dynamical regimes including chaos, limit cycles, and bifurcations through detailed phase portraits and bifurcation analysis.

Contribution

It introduces a novel visualization approach using phase portraits in intensity versus voltage, offering unprecedented insight into laser dynamics and transitions to chaos.

Findings

Identified route to chaos interrupted by limit cycles and subharmonic regimes.

Mapped bifurcation diagrams showing transitions in laser dynamics.

Provided visual and quantitative analysis of laser behavior under feedback.

Abstract

We map the phase-space trajectories of an external-cavity semiconductor laser using phase portraits. This is both a visualization tool as well as a thoroughly quantitative approach enabling unprecedented insight into the dynamical regimes, from continuous-wave through coherence collapse as feedback is increased. Namely, the phase portraits in the intensity versus laser-diode terminal-voltage (serving as a surrogate for inversion) plane are mapped out. We observe a route to chaos interrupted by two types of limit cycles, a subharmonic regime and period-doubled dynamics at the edge of chaos. The transition of the dynamics are analyzed utilizing bifurcation diagrams for both the optical intensity and the laser-diode terminal voltage. These observations provide visual insight into the dynamics in these systems.