{TAIL ~ means} for regulating comprises a transistor circuit for controlling the discharge current from {HEAD ~ the source} of laser light 
{ TAIL ~ means } for regulating comprises a transistor circuit for controlling the discharge current from { HEAD ~ the source } of laser light
TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH