ARRAY WAVEGUIDE GRATING ELEMENT

摘要

PROBLEM TO BE SOLVED: To make it possible to stably produce an element having a good wavelength characteristic at a low cost by inserting a filter for removing a higher mode in part of waveguides of an optical waveguide circuit. SOLUTION: The array waveguide grating element 10 comprises at least >=1 piece of an input waveguide 11, a first slab waveguide (region) 12, array waveguide gratings 13, a second slab waveguide (region) 14 and at least >=1 of output waveguides 15 connected to the terminal part of the second slab waveguide (region) 14 and the end of the slab waveguide (region) 14. The higher mode filter 16 for removing the higher mode of the waveguides is inserted into any of the input waveguide 11, the output waveguides 15 and the array waveguide gratings 13 or the whole thereof. The higher mode filter 16 consists of the input/output waveguide and a multimode interference region broader than the same and the output characteristic thereof is determined by the width and length of the multimode interference region by the interference phenomenon between the modes in the broad multimode interference region.