Design of a monolithic source of photon pairs comprising a semiconductor laser and a Bragg reflection waveguide

TL;DR

This paper presents a novel monolithic, electrically driven photon pair source using a non-linear AlGaAs Bragg reflection waveguide integrated with a laser, achieving high efficiency and photon pair rates suitable for quantum applications.

Contribution

It introduces a new integrated photon pair source design combining a laser and a Bragg reflection waveguide with lateral tapers for efficient mode coupling, avoiding doping-related losses.

Findings

Coupling efficiency of 28% between laser and waveguide modes.

Photon pair rate of 1.7×10^8 pairs/sec at 1550 nm for a 2 mm device.

No doping required, reducing parasitic losses.

Abstract

We propose a monolithic, electrically driven source of photon pairs based on a non-linear AlGaAs Bragg reflection waveguide and a laser structure stacked on top. By introducing lateral tapers, the fundamental mode of the lasing waveguide is vertically coupled into a higher order mode of the Bragg reflection waveguide (Bragg mode) such that photon pairs can be generated through a type-II spontaneous parametric down conversion process. According to numerical simulations, a coupling efficiency of 28% is achieved between both modes. Phase matching the Bragg mode with two fundamental modes at 1550 nm results in a photon pair rate of 1.7*10^8 pairs/s for a 2 mm long device assuming 1 mW of power in the Bragg mode. Since the Bragg reflection waveguide does not require doping for this vertically coupled structure, free-carrier absorption losses and parasitic luminescence are avoided.