However, in Patent Publication 4, only directions of the three splitting waveguides of {HEAD ~ the Y type waveguide element} for connecting them to each other are described and there is {TAIL ~ no concrete description} regarding a method of designing a Y type waveguide element so that optical outputs to the N output waveguides or ports are equally distributed 
However , in Patent Publication 4 , only directions of the three splitting waveguides of { HEAD ~ the Y type waveguide element } for connecting them to each other are described and there is { TAIL ~ no concrete description } regarding a method of designing a Y type waveguide element so that optical outputs to the N output waveguides or ports are equally distributed
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH