OPA857: Increasing sensitivity of OPA857

Dear All,

I started from the reference design TIDA-00663.  For the photodiode I use the SFH 2400 (wider spectral response) instead of the SFH 2400FA (only sensitive in infrared).  The laser was changed to a 5 mW 640 nm instead if the 70 W (!!) 900 nm laser due to safety considerations.

Is there a way to increase the sensitiviy of the OPA857 or do I have to rethinks the sensor side entirely?

Thanks for your comments.