Control of emission interval and timing in triggered periodic superradiance

TL;DR

This paper demonstrates how a trigger laser can precisely control the timing and interval of superradiance emission in an Er:YSO crystal, enhancing coherence development and enabling targeted emission timing.

Contribution

It introduces a method to control superradiance period and timing using a trigger laser, supported by numerical simulations and experimental validation.

Findings

Trigger laser reduces superradiance period and variance.

Increased trigger laser power decreases emitted photons proportionally.

Superradiance can be initiated with insufficient excitation laser using trigger pulses.

Abstract

To achieve more controllable development of coherence in solids, we investigated the effect of a trigger laser tuned to the superradiance transition wavelength on periodic superradiance observed in an Er:YSO crystal. For period control, applying the trigger laser reduced both the superradiance period and its variance, demonstrating enhanced controllability of coherence development dynamics. As the trigger laser power increased, both the period and the number of emitted superradiance photons decreased while maintaining a proportional relationship. This behavior is explained by a reduced superradiance threshold under a constant excitation rate and is reproduced by numerical simulations based on the Maxwell-Bloch equations. For timing control, we found that superradiance could be triggered even when the excitation laser alone was insufficient. This enabled us to control the emission timing of superradiance using short trigger pulses and provided a device capable of generating superradiance at desired timing.