{TAIL ~ A laser system} using a cw HeNe laser for transmitting {HEAD ~ a beam} through a dioic into an unstable resonator 
{ TAIL ~ A laser system } using a cw HeNe laser for transmitting { HEAD ~ a beam } through a dioic into an unstable resonator
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH