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