Without the phase matching, while the initial input light has the desired shape, this shape is not retained throughout {HEAD ~ the traversal} of {TAIL ~ the fiber} 
of
Without the phase matching , while the initial input light has the desired shape , this shape is not retained throughout { HEAD ~ the traversal } of { TAIL ~ the fiber }
OTH OTH OTH OTH OTH OTH OTH OTH OTH 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