Enhancement of light emission in Bragg monolayer-thick quantum well structures

TL;DR

This paper demonstrates super-radiance in a cavity-less Bragg structure with monolayer-thick quantum wells, showing enhanced emission rates and potential for cavity-less laser applications.

Contribution

It experimentally shows super-radiance in a cavity-less structure, a novel approach for enhancing light emission without traditional cavities.

Findings

Super-radiance observed in Bragg structures.

Enhanced emission at specific angles and frequencies.

Correlation with increased Purcell coefficient near Bragg condition.

Abstract

Control over spontaneous emission rate is important for improving efficiency in different semiconductor applications including lasers, LEDs and photovoltaics. Usually, an emitter should be placed inside the cavity to increase spontaneous emission rate, although it is technologically challenging. Here we experimentally demonstrate a phenomenon of super-radiance observed in a cavity-less periodic Bragg structure based on InAs monolayer-thick multiple quantum wells (MQW). The collective super-radiant mode shows enhanced emission rate for specific angles and frequencies. This behaviour correlates with the calculations demonstrating individual spots of enhanced Purcell coefficient near the Bragg condition curve. This study provides a perspective for realization of surface emitting cavity-less lasers with distributed feedback.