Electro-optic modulator based gate transient suppression for sine-wave gated InGaAs/InP single photon avalanche photodiode

Abstract. Capacitive gate transient noise has been problematic for the high-speed single photon avalanchephotodiode (SPAD), especially when the operating frequency extends to the gigahertz level. We proposedan electro-optic modulator based gate transient noise suppression method for sine-wave gated InGaAs/InPSPAD. With the modulator, gate transient is up-converted to its higher-order harmonics that can be easilyremoved by low pass filtering. The proposed method enables online tuning of the operating rate without modi-ficationofthehardwaresetup.At250K,detectionefficiencyof14.7%wasobtainedwith4.8×10 −6 pergatedarkcount and 3.6% after-pulse probabilities for 1550-nm optical signal under 1-GHz gating frequency. Experimentalresults have shown that the performance of the detector can be maintained within a designated frequencyrangefrom 0.97 to 1.03 GHz, which is quite suitable for practical high-speed SPAD applications operated around thegigahertz level. © 2014 Society of Photo-Optical Instrumentation Engineers (SPIE) [DOI: 10.1117/1.OE.53.6.067102]