{HEAD ~ a laser} optically coupled to said first light input via a first optical fiber and optically coupled to {TAIL ~ said second light input} via a second optical fiber 
optically coupled to
{ HEAD ~ a laser } optically coupled to said first light input via a first optical fiber and optically coupled to { TAIL ~ said second light input } via a second optical fiber
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH