Definition of the stimulated emission threshold in high-$\beta$ nanoscale lasers through phase-space reconstruction

Abstract

Nanoscale lasers sustain few optical modes so that the fraction of spontaneous emission $\beta$ funnelled into the useful (lasing) mode is high (of the order of few 10${}^{-1}$) and the threshold, which traditionally corresponds to an abrupt kink in the light in- light out curve, becomes ill-defined. We propose an alternative definition of the threshold, based on the dynamical response of the laser, which is valid even for $\beta =1$ lasers. The laser dynamics is analyzed through a reconstruction of its phase-space trajectory for pulsed excitation. Crossing the threshold brings about a change in the shape of the trajectory and in the area contained in it. An unambiguous definition of the threshold in terms of this change is shown theoretically and illustrated experimentally in a photonic crystal laser.

References in corpus (2)

• Demonstration of coherent emission from high-$\beta$ photonic crystal nanolasers at room temperature
• Transient chirp in high speed photonic crystal quantum dots lasers with controlled spontaneous emission

Cited by in corpus (4)

• "Phase Transitions" in small systems: why standard threshold definitions fail for nanolasers
• Controlling the gain contribution of background emitters in few-quantum-dot microlasers
• Spontaneous-emission-enabled dynamics at the threshold of a directly modulated semiconductor laser
• Inherent Stochastic Linearization of Random Laser Modes