A laser unit includes {TAIL ~ a semiconductor laser tip} mounted on a substrate of {HEAD ~ a material} such as Si, a monitoring photodiode, and a laser driving integrated circuit, all of which are fixed to a base member of a material, such as metal, by soldering or the like 
A laser unit includes { TAIL ~ a semiconductor laser tip } mounted on a substrate of { HEAD ~ a material } such as Si , a monitoring photodiode , and a laser driving integrated circuit , all of which are fixed to a base member of a material , such as metal , by soldering or the like
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD 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 OTH OTH OTH OTH OTH OTH OTH OTH