Optical circuit
AssigneeNippon Telegraph and Telephone Corporation
InventorsJunji Sakamoto, Tomohiro Inaba, Toshikazu Hashimoto
Life of this patent
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Abstract
There is a manufacturing error even if an RGB coupler is appropriately designed, and thus a problem that it is difficult to achieve the function as designed with good yield arises. To solve this problem, an optical circuit with a first waveguide in which light in a zero-th order mode is guided and a second waveguide having a larger width than the first waveguide, in which light in a primary mode is guided in which the first and second waveguides at least include a first curved portion in a curve shape curved toward the first waveguide while maintaining a combination of waveguide widths satisfying mode conversion conditions is provided.
Claims10
An optical circuit comprising:
- a first waveguide configured to guide light in an N-th order mode (N is an integer satisfying N≥0);
- a second waveguide, having a larger width than the first waveguide, configured to guide light in an M-th order mode (M is an integer satisfying M>N);
- and
- a third waveguide configured to guide light in the N-th order mode, the third waveguide having a width that is the same as the width of the first waveguide,
- wherein the first waveguide, the second waveguide, and the third waveguide are placed side by side in this order in a manner that the first waveguide, the second waveguide, and the third waveguide do not contact each other,
- wherein the second waveguide includes at least a first curved portion in a curve shape curved toward the first waveguide while maintaining a combination of waveguide widths satisfying a mode conversion condition,
- wherein the second waveguide and the third waveguide include, in a posterior stage of the first curved portion, a second curved portion in a curved shape curved toward the third waveguide while maintaining a combination of waveguide widths satisfying the mode conversion condition, and
- wherein the first and third waveguides curve with the second waveguide.
Dependencies are inferred from the claim text.