Design study for an efficient semiconductor quantum light source operating in the telecom C-band based on an electrically-driven circular Bragg grating

TL;DR

This paper presents a detailed design of an electrically-driven circular Bragg grating in InP for efficient single-photon sources operating in the telecom C-band, with high collection efficiency and Purcell factors.

Contribution

It introduces a novel design of a circular Bragg grating device compatible with electrical injection, achieving high efficiency and Purcell enhancement in the telecom wavelength range.

Findings

Collection efficiency close to 90% in 1520-1580 nm range

Purcell factor up to 20 with electrical injection design

Coupling into single mode fiber exceeds 70%

Abstract

The development of efficient sources of single photons and entangled photon pairs emitting in the low-loss wavelength region around 1550 nm is crucial for long-distance quantum communication. Moreover, direct fiber coupling and electrical carrier injection are highly desirable for deployment in compact and user-friendly systems integrated with the existing fiber infrastructure. Here we present a detailed design study of circular Bragg gratings etched in InP slabs and operating in the telecom C-band. These devices enable the simultaneous enhancement of the X and XX spectral lines, with collection efficiency in NA=0.65 close to 90% for the wavelength range 1520-1580 nm and Purcell factor up to 15. We also investigate the coupling into single mode fiber, which exceeds 70% in UHNA4. Finally, we propose a modified device design directly compatible with electrical carrier injection, reporting Purcell factors up to 20 and collection efficiency in NA=0.65 close to 70% for the whole telecom C-band.