a package containing the array of light emitting elements and the substrate, {HEAD ~ the package} enclosed with {TAIL ~ a window}, wherein the window has two surfaces 
a package containing the array of light emitting elements and the substrate , { HEAD ~ the package } enclosed with { TAIL ~ a window } , wherein the window has two surfaces
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH