Optical multiplexing / demultiplexing device and arrayed waveguide diffraction grating type optical wavelength filter

摘要

To provide an optical multiplexing / demultiplexing element in which radiation loss generated in a connecting portion between a slab waveguide and a waveguide structure is reduced.SOLUTION: This optical multiplexing / demultiplexing element is provided with a slab waveguide 11 and a waveguide structure 4. In the waveguide structure 4, the MMI waveguide coupler 14, the first tapered waveguide 15, the wide waveguide 16, and the second tapered waveguide 17 are arranged in this order along the waveguide direction from the connection position with the slab waveguide 11 It is connected. The waveguide cores that constitute the MMI waveguide coupler 14, the first tapered waveguide 15, and the part connecting the first tapered waveguide 15 to the middle of the wide waveguide 16 are arranged along the waveguide direction in the left waveguide A region L, a central waveguide region C, and a right waveguide region R are set. The thicknesses of the left waveguide region L and the right waveguide region R are thinner than the thickness of the central waveguide region C and the left waveguide region L and the right waveguide region R are symmetrical with respect to the central waveguide region C Is formed.(FIG.