Traditionally, photodiodes operate at static reverse bias, and incident light intensity is obtained from the relatively week photocurrent. In this paper, we introduce a different concept of photodiode function: the photodiode is used in a dynamic regime where it is switched from the reverse to forward state. Thus, the light intensity is defined not by the measured photocurrent but by the delay time of appearance of the strong forward current with the amplitude independent of the light intensity. Our experimental results as well as finite element modeling show that the dynamic mode of photodiode operation can potentially provide an improvement of the device performance. (C) 2015 AIP Publishing LLC.