Optical multiplexing and de-multiplexing element and arrayed-waveguide grating-type optical wavelength filter
AssigneesOki Electric Industry Co., Ltd., Photonics Electronics Technology Research Association
InventorHideaki Okayama
Life of this patent
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Abstract
There is provided an optical multiplexing and de-multiplexing element which is provided with a slab waveguide and a waveguide structure and can reduce radiation loss caused in a connection part between the slab waveguide and the waveguide structure. The waveguide structure includes a multimode interference (MMI) waveguide coupler and a narrow-width waveguide, the MMI waveguide coupler and the narrow-width waveguide are connected to each other in this order from a connection position with the slab waveguide along the waveguide direction, step portions are formed on both sides of the MMI waveguide coupler along the waveguide direction, and the thickness of the step portion is smaller than the thickness of the MMI waveguide coupler.
Claims7
An optical multiplexing and de-multiplexing element, comprising:
- a slab waveguide;
- and
- a waveguide structure, the waveguide structure including
- a multi-mode interference (MMI) waveguide coupler and a narrow-width waveguide, the MMI waveguide coupler connected between the narrow-width waveguide and the slab waveguide along a first direction defining a waveguide direction, and
- step portions formed on both sides of the MMI waveguide coupler and extending along the sides of the MMI waveguide coupler in the waveguide direction,
- wherein a thickness of each step portion is less than a thickness of the MMI waveguide coupler, and
- a length of each step portion, from the slab waveguide towards the narrow-width waveguide, along the waveguide direction is equal to a length of the MMI waveguide coupler, from the slab waveguide towards the narrow-width waveguide, along the waveguide direction.
Dependencies are inferred from the claim text.