The method 12, further comprising affixing {HEAD ~ the birefringent displacer} on a mounting frame with {TAIL ~ respect} to an optical path of the input beam after the minimum PDL is found 
The method 12 , further comprising affixing { HEAD ~ the birefringent displacer } on a mounting frame with { TAIL ~ respect } to an optical path of the input beam after the minimum PDL is found
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH