On collective Rabi splitting in nanolasers and nano-LEDs

TL;DR

This paper analytically investigates the optical emission spectra of nanolasers and nano-LEDs, revealing conditions for collective Rabi splitting and how pump rates influence spectral features and linewidths.

Contribution

It provides a theoretical analysis of collective Rabi splitting in nanolasers and nano-LEDs, clarifying the spectral signatures and differences between emission spectra and eigenmodes.

Findings

Double-peaked spectra indicate collective Rabi splitting at low pump rates.

Nano-LEDs do not show spectral splitting despite having distinct eigenmodes.

Increasing pump rate merges the peaks into a single one.

Abstract

We analytically calculate the optical emission spectrum of nanolasers and nano-LEDs based on a model of many incoherently pumped two-level emitters in a cavity. At low pump rates we find two peaks in the spectrum for large coupling strengths and numbers of emitters. We interpret the double-peaked spectrum as a signature of collective Rabi splitting, and discuss the difference between the splitting of the spectrum and the existence of two eigenmodes. We show that an LED will never exhibit a split spectrum, even though it can have distinct eigenmodes. For systems where the splitting is possible we show that the two peaks merge into a single one when the pump rate is increased. Finally, we compute the linewidth of the systems, and discuss the influence of inter-emitter correlations on the lineshape.