{HEAD ~ dichroic means} for reflecting said first beam in a third direction and for transmitting {TAIL ~ said second beam} therewith whereby said second beam follows said first beam 
for transmitting
{ HEAD ~ dichroic means } for reflecting said first beam in a third direction and for transmitting { TAIL ~ said second beam } therewith whereby said second beam follows said first beam
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH