In {TAIL ~ a dual focusing optical pickup device}, a laser beam is incident on {HEAD ~ an optical member} via a beam splitter 
In { TAIL ~ a dual focusing optical pickup device } , a laser beam is incident on { HEAD ~ an optical member } via a beam splitter
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH