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