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