Modeling of photocurrent and dark count probability of InGaAs/ InP Single Photon Avalanche Photodiode

Single photon avalanche detector is widely used for the optical detection of weak signals utilizing photocurrent multiplication mechanism beyond the breakdown voltage. In the present work, photocurrent characteristics of InGaAs/InP based SPAD device are analysed. The device in the model employs self-differencing method and operates in gated mode with 1GHz gating frequency in near infrared region. Dark count probabilities have been generated for varying single photon detection efficiency (SPDE). The results of current-voltage characteristics (for operating temperatures -50, -30, 0 and 20 degree Celsius) and dark count probability as a function of SPDE have been examined by comparing them with published experimental results. Error analysis shows that the deviation of the present model from the experimental results is low in room temperature and agrees with the experimental values within 3% range.