Anode 60 of {TAIL ~ photodiode} 58 is common with {HEAD ~ inverting terminal} 74 of op amp 70 
Anode 60 of { TAIL ~ photodiode } 58 is common with { HEAD ~ inverting terminal } 74 of op amp 70
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH