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

Thanks to the long group delay of the SAW filter, the UNIC interferometer can produce an ultra-narrrow band rejection with a manufacturing tolerance easily achievable in the RF track lengths.

The UNIC can provide a wide and continuous pass band in the frequency domain and therefore brings little distortion into the avalanche signal. The team reports their development of a standalone InGaAs SPD module that fully integrates driving and readout electronics as well as temperature regulation and compensation.

Its dimension is measured just 8.8×6×2 cm³ and is nearly a factor of 4 smaller in volume than the most compact existing detector module that uses a monolithically integrated readout circuit. Simultaneously, this size reduction does not bring performance deterioration.

The research team uses their previous UNIC techniques for the APD signal readout, but adds an automatic temperature compensation to ensure an optimal performance over a wide ambient temperature range.

With a 1.25 GHz clock input, the module is characterized to have comparable performance to its counterpart built with benchtop equipment. The UNIC-SPD exhibits excellent performance with a net detection efficiency of 30% at an afterpulsing probability of 2.4 % under 3 ns hold-off time. The compact size and state-of-the-art performance allow the UNIC-SPD module a huge potential for single-photon imaging and high-speed quantum key distribution.

More information:
Haoyang Wang et al, Progress on Chip-Based Spontaneous Four-Wave Mixing Quantum Light Sources, Advanced Devices & Instrumentation (2023). DOI: 10.34133/adi.0032

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Advanced Devices & Instrumentation