Quantum-dot nano-cavity lasers with Purcell-enhanced stimulated emission

Abstract

We present a rate equation model for quantum-dot light-emitting devices that take into account Purcell enhancement of both spontaneous emission and stimulated emission as well as the spectral profile of the optical and electronic density-of-states. We find that below threshold the β-factor in a quantum-dot nanolaser depends strongly on the pump. For quantum dots with linewidth comparable to that of the cavity, we then show that an otherwise non-lasing device can lase due to Purcell enhancement of the stimulated emission. Finally, we compare the rate equation model to a microscopic model and obtain good agreement.

Theory of nanolaser devices: Rate equation analysis versus microscopic theory

“…The definition (16) for the background emission is necessary for subsequent comparison with our microscopic model which requires a fixed β, i.e., independent of the carrier number. In Appendix A we present the general procedure for computing the β factor.…”

“…The intention of this paper is to clarify this situation by bridging the gap between a purely microscopic approach and a rate equation model that is suited for implementation in large-scale device simulations. We thus present the detailed derivation of our recently published rate equation model, 16 which naturally extends our previous models valid in the LED regime of spontaneous emission, 14,16 to account for spontaneous and stimulated emission rates in a self-consistent way.…”

“…9 Therefore, the laser dynamics of nanocavity-based laser devices has been a much debated topic in recent years (see, e.g., Refs. [10][11][12][13][14][15][16].…”

Random nanolasing in the Anderson localized regime

“…Two important figures of merit of a nanolaser are its b-factor (the fraction of spontaneous emission that couples to the lasing mode) and the cavity mode volume (the spatial extension of the lasing mode). These can be determined by modelling the laser input-output curves with microcavity semiconductor laser rate equations 22 (cf. Fig.…”

Optical properties of organic-silicon photonic crystal nanoslot cavity light source

“…8,33 Neglecting the Purcell enhancement of stimulated emission would overlook the finite linewidth of the lasing modes, and result into a solution contradictory to the Einstein relation 34 and the prediction of microscopic model. 35 Therefore, it was suggested that a comprehensive rate equation analysis 36,37 including the aforementioned experimental evidences should be used. In this work, by means of a full rate equation model including the complete cavity QED effects, we can accurately investigate the optical properties of our organic-silicon PC nanoslot cavity light source in a self-consistent fashion.…”