In addition to {HEAD ~ light} from {TAIL ~ the light source} 74, the imaging optics 78 also receive a locator beam 90 from an infrared light source 92 carried by a common substrate 85 with the light source 74 
from
In addition to { HEAD ~ light } from { TAIL ~ the light source } 74 , the imaging optics 78 also receive a locator beam 90 from an infrared light source 92 carried by a common substrate 85 with the light source 74
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH