A chip-scale, telecommunications-band frequency conversion interface for quantum emitters

TL;DR

This paper presents a chip-scale frequency conversion interface using silicon nitride waveguides for quantum emitters, enabling efficient wavelength translation in the telecommunications band with low noise.

Contribution

It introduces a novel integrated frequency conversion device for quantum emitters, demonstrating low-noise operation and potential for high efficiency at higher input powers.

Findings

Achieved >10 signal-to-background ratio in frequency conversion

Demonstrated approximately -60 dB conversion efficiency at low pump powers

Projected >25% conversion efficiency at higher input powers

Abstract

We describe a chip-scale, telecommunications-band frequency conversion interface designed for low-noise operation at wavelengths desirable for common single photon emitters. Four-wave mixing Bragg scattering in silicon nitride waveguides is used to demonstrate frequency upconversion and downconversion between the 980 nm and 1550 nm wavelength regions, with signal-to-background levels >10 and conversion efficiency of approximately -60 dB at low continuous wave input pump powers (<50 mW). Finite element simulations and the split-step Fourier method indicate that increased input powers of approximately 10 W (produced by amplified nanosecond pulses, for example) will result in a conversion efficiency >25 % in existing geometries. Finally, we present waveguide designs that can be used to connect shorter wavelength (637 nm to 852 nm) quantum emitters with 1550 nm.