Incidentally, the BPW34 PIN diode has 25 pF capacitance at 3V reverse bias, so your simulations were spot on.
This gives nice output from 1nA - 500nA diode pulses.. (inp. noise not considered). Diode pulse: 20ns duration and 20ns rising/falling edges. Parts used are an example only. Use the best one you can get No warranties of any kind, provided as-is..