A waveguide device has an input waveguide, a plurality of output
waveguides, a channel waveguide array, an input slab waveguide, and an
output slab waveguide. The output slab waveguide connects an output end of
the channel waveguide array to the output waveguide, and has optical
input/output characteristics set to given ratios for the output waveguides
with respect to the input waveguides. The waveguide device is capable of
adjusting signal levels output from the respective waveguides without the
need for circuit parts for compensating for loss differences and also the
need for a process of highly accurately attaching parts.
