{TAIL ~ The laser beam b} having the P polarized component left due to the retardation defect passes through {HEAD ~ the polarizing beam splitter} 3 to be left as laser beam d 
{ TAIL ~ The laser beam b } having the P polarized component left due to the retardation defect passes through { HEAD ~ the polarizing beam splitter } 3 to be left as laser beam d
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH