A structure including {TAIL ~ a grating} and a semiconductor nanocrystal layer on {HEAD ~ the grating}, can be a laser 
A structure including { TAIL ~ a grating } and a semiconductor nanocrystal layer on { HEAD ~ the grating } , can be a laser
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH