An optical isolator element which is disposed in {HEAD ~ front} of a laser array comprised of {TAIL ~ a plurality} of laser active regions arranged in parallel, comprising 
An optical isolator element which is disposed in { HEAD ~ front } of a laser array comprised of { TAIL ~ a plurality } of laser active regions arranged in parallel , comprising
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH