The second diffractive structure may be adapted to output {HEAD ~ light} having {TAIL ~ corkscrew wave} 
having
The second diffractive structure may be adapted to output { HEAD ~ light } having { TAIL ~ corkscrew wave }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL