I am using PIN photodiode BPW34 (1).
I am then using an opamp (LM324) (2) to amplify and get an output voltage from the current source generated through the photodiode.
Following is the circuit I am using to realise this.
Following is the output I am getting at particular frequencies. I am actually giving square wave input light signal to photodiode.Following image is the output we got from the digital oscilloscope(Left-400kHz,Right-2kHz).
I also tried changing parameters for Cf in the diagram and also putting direct square wave voltage source(Left image) instead of photodiode with equivalent resistance.
Following is the output I got.
After all the experimentations, I feel that frequency response is sluggish(Right image) due to RC limitations of the circuits and that too due to capacitance of photodiode.
Someone please suggest me something for the same. I have read a lot of documents related to the same but couldn't find anything that is concrete.