Progress on chip-based spontaneous four-wave mixing quantum light sources

https://phys.org/news/2024-02-chip-based-spontaneous-quantum-sources.html

"surface acoustic wave filter + asymmetric radio-frequency Mach-Zehnder interferometer ultra-narrowband interference circuit with narrow-band rejection of SPD capacitive response... wide, continuous pass band, so little distortion into avalanche signal... integrates driving and readout electronics... automatic temperature compensation optimized over wide ambient range... 4X smaller... 1.25 GHz clock input, net detection efficiency 30%... single-photon imaging, high-speed quantum key distribution"