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