Time-Resolved dynamics of semiconductor nanolaser via four-wave mixing gating

TL;DR

This paper demonstrates a novel four-wave mixing gating technique for direct, time-resolved measurement of ultrafast nanolaser emission dynamics at telecom wavelengths, revealing the influence of noise and pulse timing.

Contribution

It introduces a nonlinear optical gating method for nanolaser characterization with picosecond resolution, advancing the understanding of nanolaser temporal behavior.

Findings

Time jitter from spontaneous emission dominates temporal broadening.

Adding a CW component reduces build-up time and makes emission deterministic.

The method achieves picosecond resolution in nanolaser dynamics measurement.

Abstract

We experimentally demonstrate the direct time-domain characterization of photonic-crystal nanolasers at telecom wavelengths using a nonlinear optical gating technique based on four-wave mixing. This approach enables the temporal characterization of the ultrafast emission dynamics under short-pulse excitation with picosecond time resolution. When a weak continuous-wave component is added to the pulsed pump, the emission becomes deterministic and the build-up time is considerably reduced. The difference between purely pulsed and hybrid excitation regimes points to the influence of pulse-to-pulse timing fluctuations. To elucidate this effect, we perform Langevin-based simulations that reproduce the experimentally observed broadening and confirm that time jitter, originating from spontaneous-emission noise near threshold, dominates the temporal dispersion. These results establish four-wave-mixing gating as a powerful method to probe nanolaser dynamics with picosecond precision.