An Optical Parametric Amplifier via $ \chi^{(2)} $ in AlGaAs Waveguides

TL;DR

This paper demonstrates significant parametric gain using $ \\chi^{(2)} $ non-linearities in AlGaAs waveguides, enabling highly sensitive, polarization-insensitive, on-chip quantum applications within a compact device footprint.

Contribution

It introduces a novel AlGaAs Bragg Reflection Waveguide with $ \\chi^{(2)} $ non-linearity achieving high gain and ultra-low photon sensitivity, advancing integrated quantum photonics.

Findings

Over 18 dB of parametric gain in 100 micrometer devices

Polarization insensitive gain in the 1550 nm spectrum

Sensitivity reaching 0.1 photons per pulse

Abstract

We report parametric gain by utilizing $ \chi^{(2)} $ non-linearities in a semiconductor Bragg Reflection Waveguide (BRW) waveguide chip. Under the two-mode degenerate type II phase matching, it can be shown that more than 18 dBs of parametric gain for both TE and TM modes is tenable in 100s of micrometers of device length. Polarization insensitive parametric gain can be attained within the 1550 nm region of the spectrum. These AlGaAs BRW waveguides exhibit sub-photon per pulse sensitivity. This is in sharp contrast to other types of parametric gain devices which utilize $ \chi^{(3)} $, where the pump wavelength is in the vicinity of the signal wavelength. This sensitivity, which reached 0.1~photon/pulse, can usher a new era for on-chip quantum information processing using compact, micrometer-scale devices.