Hi likhil,
connect the photodiode or DUT to a current/voltage amplifier (transimpedance amplifier) the output of the amplifier, should be ac or use a dc blocking element, connect to the Signalhound.
etting Spike Software:
Trace: Type: Average
Acquisition: Video Units: Power
Detector: Average
Bandwith: RBW Shape: Flat Top
RBW:10Hz
VBW:10Hz
REF Level: -50dBm
Start: 1Hz
Stop 200kHz
Spur Reject: Off
Gain/Atten: Auto
BR
Flo