Time response of avalanche photodiodes as a function of the internal gain

Using a red LED and a blue laser as a light source, time response of avalanche photodiodes and Metal-Resistive Silicon (MRS) layer avalanche photodiodes [1]has been measured. A strong dependence of the time resolution on the internal gain has been observed. The obtained results show that the increase of the internal gain improves the time resolution. However, there exists a critical value for the internal gain. Beyond this value a deterioration of the time resolution is observed.