On the other hand, where {HEAD ~ a laser diode} of {TAIL ~ appropriate frequency} emanates narrow band radiation at the absorption frequency of the transition, the stimulation is much more efficient 
On the other hand , where { HEAD ~ a laser diode } of { TAIL ~ appropriate frequency } emanates narrow band radiation at the absorption frequency of the transition , the stimulation is much more efficient
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH