This light is reflected from a reflective layer at the output surface and from {HEAD ~ a reflective layer} at {TAIL ~ the input surface} of the member 
at
This light is reflected from a reflective layer at the output surface and from { HEAD ~ a reflective layer } at { TAIL ~ the input surface } of the member
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH