IR light from the laser is directed to the spring region of {HEAD ~ the suspension} by {TAIL ~ optical fibers} 
by
IR light from the laser is directed to the spring region of { HEAD ~ the suspension } by { TAIL ~ optical fibers }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL