, {HEAD ~ the window} has a diffractive optical element on a surface of the window closest to the array, the diffractive optical element arranged to partially collimate {TAIL ~ the light} 
, { HEAD ~ the window } has a diffractive optical element on a surface of the window closest to the array , the diffractive optical element arranged to partially collimate { TAIL ~ the light }
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL