{TAIL ~ The printed circuit board} may include an embedded optical waveguide and a first optical window extending from {HEAD ~ the optical waveguide} to a first surface of the printed circuit board 
{ TAIL ~ The printed circuit board } may include an embedded optical waveguide and a first optical window extending from { HEAD ~ the optical waveguide } to a first surface of the printed circuit board
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH