Difference-frequency generation in an AlGaAs Bragg-reflection waveguide using an on-chip electrically-pumped quantum dot laser

TL;DR

This paper demonstrates on-chip difference-frequency generation in an AlGaAs waveguide with integrated quantum dot laser, achieving efficient nonlinear conversion and paving the way for fully integrated photonic systems.

Contribution

It introduces a novel integrated AlGaAs waveguide with quantum dot laser gain medium enabling on-chip nonlinear frequency conversion.

Findings

Normalized conversion efficiency up to 0.64%/W/cm^2 achieved.

Broad modal phase-matching facilitates nonlinear processes at the laser wavelength.

Integration of active laser and nonlinear elements on a single chip demonstrated.

Abstract

Nonlinear frequency conversion is ubiquitous in laser engineering and quantum information technology. A long-standing goal in photonics is to integrate on-chip semiconductor laser sources with nonlinear optical components. Engineering waveguide lasers with spectra that phase-match to nonlinear processes on the same device is a formidable challenge. Here, we demonstrate difference-frequency generation in an AlGaAs Bragg reflection waveguide which incorporates the gain medium for the pump laser in its core. We include quantum dot layers in the AlGaAs waveguide that generate electrically driven laser light at ~790 nm, and engineer the structure to facilitate nonlinear processes at this wavelength. We perform difference-frequency generation between 1540 nm and 1630 nm using the on-chip laser, which is enabled by the broad modal phase-matching of the AlGaAs waveguide, and measure normalized conversion efficiencies up to $(0.64\pm0.21)$ %/W/cm$^2$. Our work demonstrates a pathway towards devices that utilize on-chip active elements and strong optical nonlinearities to enable highly integrated photonic systems-on-chip.