{HEAD ~ a substrate} capable of transmitting {TAIL ~ visible light} and having a pair of opposing surfaces 
capable of transmitting
{ HEAD ~ a substrate } capable of transmitting { TAIL ~ visible light } and having a pair of opposing surfaces
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH