| Summary: | 碩士 === 國立臺北科技大學 === 光電工程系 === 106 === In this thesis, the changing in temperature, excess bias and gated frequency to detect single photon using a dual avalanche photodiode (APD) scheme was proposed and demonstrated. The characteristics of single photon detection, including dark count probability (DCP), single photon detection efficiency (SPDE), noise equipment power (NEP) and afterpulsing probability, are measured and discussed.
In this work, APD1 was cooled down by TE cooler and operated excessed breakdown voltage. APD2 was operated in room temperature and bias act a proper voltage to match APD1. Then, the signals of APD1 and APD2 were self-differencing to reduce spiking noise and avalanche signal can be easy detected. Finally, the avalanche signals are observed by scope or recorded by photon counter.
Temperature of -30°C, gated frequency of 1 MHz, gated pulse of 2 ns and excess bias of 3.2 V, the best single-photon performances. In this study are : dark count probability of 2.48×10-3, single photon detection efficiency of 12.86 %, noise equipment power of 1.56×10-15 (W/Hz)1/2 and afterpulsing probability of 5.67 %.
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