Monolithic Receiver with Nine Single-Photon Avalanche Diodes

Abstract

An optical receiver containing nine single-photon avalanche diodes (SPADs) and nine active quenching circuits is presented. This optical receiver was fabricated in a 0.35μm high-voltage CMOS technology without any process modifications. The SPADs avoid the excess noise of linear-mode avalanche diode receivers and allow for a better optical sensitivity. With 680 nm light, the 9-SPAD receiver achieves a sensitivity of -56.8 dBm for a bit error ratio of 2×10 -3 at a data rate of 50 Mb/s. Compared to a 4-SPAD receiver fabricated in the same technology and introduced in 2020, the sensitivity is improved by 1.7 dB. The remaining gap to the quantum limit, which is at -73.7 dBm for 50 Mb/s, is reduced to 16.9 dB. A comparison to the state-of-the-art of SPAD receivers is included.