{HEAD ~ A semiconductor photodetector}, such as a PIN photodiode and an avalanche photodiode, comprising an InP substrate, {TAIL ~ a first InP layer}, a GaInAs or GaInAsP light absorbing layer, and a second InP layer 
comprising
{ HEAD ~ A semiconductor photodetector } , such as a PIN photodiode and an avalanche photodiode , comprising an InP substrate , { TAIL ~ a first InP layer } , a GaInAs or GaInAsP light absorbing layer , and a second InP layer
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH