Abstract
We report a near infrared (NIR) single photon detector (SPD) using an InGaAs/InP avalanche photodiode (APD) operated with a bipolar rectangular gating signal. The use of the bipolar gating pulse enabled us to operate the APD well below the breakdown voltage during the gate-off time. As a result, it permits to decrease the lifetime of the trapped carriers, and then reduces the after-pulse noise of the detector. At a repetition rate of 200 MHz, the after-pulse probability is 8.2% less comparing to that of conventional gating signal SPD. (C) 2012 The Japan Society of Applied Physics