PIN diode in RF switching vs. PIN diode used as photodiode
Yes. 

Have a look at this thesis - A picosecond optoelectronic cross correlator using a gain modulated avalanche photodiode for measuring the impulse response of tissue
David Kirkby, April 1999 discovery.ucl.ac.uk/1456753/1/D_R_Kirkby_PhD_Thesis.pdf