Thanks for comments. Here is a bit more detail.
The second stage provides a gain of -160, with R1=4k7 & R2=750k. During testing I didn't have the second stage driving anything.
I have made some modifications which have helped the circuit. Firstly, the photodiode was not across the OPAs inputs...
I desperately require some circuitry advice before I go mad!
I have built some interface circuits for silicon photodiodes (quadrant detector) which seem to work on a knife edge.
I have tried different op amps with low input bias currents, all have not seemed immuned from problems. In the latest...
