applying a voltage across {TAIL ~ each extraction diode} for operating each extraction diode only reverse biased and electrically isolating {HEAD ~ each} of said photodiodes 
applying a voltage across { TAIL ~ each extraction diode } for operating each extraction diode only reverse biased and electrically isolating { HEAD ~ each } of said photodiodes
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH