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