OPTICAL MULTIPLEXING ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a demultiplexing device small in size while having excellent characteristics as a wavelength demultiplexing device having a structure having core layers and clad layers of an input and an output core layer exposed to air. SOLUTION: This optical multiplexing element is so constituted as to have an optical multiplexing part consisting of input waveguides 13, at least one output waveguide 14, and a slab wave guide 12 by including a nesa formed by laminating a core layer 15 and clad layers 16 and 17 across the core layer 15 as the input waveguides 13 and output waveguide 14. In this case, the width of the slave waveguide 12 is made large so that none of input light which is guided spreading in the slab waveguide 12 is reflected by the flank of the slab waveguide 12 and coupled with the output waveguide 14.