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