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