# Emission spectrum of broadband quantum dot superluminescent diodes

## TL;DR

This paper develops a microscopic quantum theory for broadband quantum dot superluminescent diodes, accurately predicting their emission spectra and correlations, aligning well with experimental observations.

## Contribution

It introduces a comprehensive multimode quantum model that derives all orders of correlation functions and predicts emission spectra, advancing understanding of quantum dot superluminescent diodes.

## Key findings

- External power spectrum as a convolution of intra-diode spectrum with Lorentzian response
- Gaussian light-matter coupling yields Gaussian output spectrum
- Model agrees well with experimental data

## Abstract

We present a microscopic theory of the amplified spontaneous emission of a spectrally broadband quantum dot superluminescent diode within the quantum white noise limit. From this multimode quantum theory, we have the ability to obtain all orders of temporal correlation functions. In particular, we derive rate equations for the optical power densities, the level occupation of inhomogeneous ensemble of quantum dots within the diode, as well as the emitted optical spectra. As the main result, we find the external power spectrum as a convolution of the intra-diode photon spectrum with a Lorentzian response. Assuming a Gaussian light-matter coupling results in a similar shaped Gaussian output spectrum, which agrees very well with available experimental data.