Broadband Purcell enhanced emission dynamics of quantum dots in linear photonic crystal waveguides

TL;DR

This study demonstrates that quantum dots embedded in photonic crystal waveguides exhibit significantly enhanced emission due to Purcell effects, enabling efficient broadband surface emission for quantum photonic applications.

Contribution

It provides the first detailed measurement of Purcell-enhanced emission dynamics of quantum dots in photonic crystal waveguides, highlighting their potential for efficient light sources.

Findings

Photoluminescence intensity is enhanced by ~21x for resonant quantum dots.

Purcell factors up to ~4x are achieved, indicating strong emission enhancement.

Emission into guided modes is efficiently scattered out, enabling broadband surface emission.

Abstract

The authors investigate the spontaneous emission dynamics of self-assembled InGaAs quantum dots embedded in GaAs photonic crystal waveguides. For an ensemble of dots coupled to guided modes in the waveguide we report spatially, spectrally, and time-resolved photoluminescence measurements, detecting normal to the plane of the photonic crystal. For quantum dots emitting in resonance with the waveguide mode, a ~21x enhancement of photoluminescence intensity is observed as compared to dots in the unprocessed region of the wafer. This enhancement can be traced back to the Purcell enhanced emission of quantum dots into leaky and guided modes of the waveguide with moderate Purcell factors up to ~4x. Emission into guided modes is shown to be efficiently scattered out of the waveguide within a few microns, contributing to the out-of-plane emission and allowing the use of photonic crystal waveguides as broadband, efficiency-enhancing structures for surface-emitting diodes or single photon sources.