{HEAD ~ a beam supplying unit} for supplying an incident laser beam including data read from {TAIL ~ a plurality} of tracks on a holographic medium 
{ HEAD ~ a beam supplying unit } for supplying an incident laser beam including data read from { TAIL ~ a plurality } of tracks on a holographic medium
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH