Photomask, optical-waveguide, optical circuit and method of manufacturing an optical-waveguide
AssigneeNTT, Inc.
InventorsTakashi Go, Ai Yanagihara, Keita Yamaguchi, Kenya Suzuki
Life of this patent
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Abstract
In an optical circuit divided into a plurality of partial circuits, an optical waveguide having a low optical loss at a connection portion is provided. A photomask in which a waveguide pattern of an optical circuit is divided into a plurality of regions and drawn, the photomask including a waveguide pattern for drawing a joint region in which a waveguide width changes as a waveguide goes toward an outer peripheral portion, to connect a plurality of the waveguides divided and drawn to each other, in which the waveguides are connected to each other by overlapping the joint regions of two of the photomasks and performing exposure.
Claims8
A photomask in which a waveguide pattern of an optical circuit is divided into a plurality of regions and drawn, the photomask comprising:
- a first photomask and a second photomask;
- in order to connect waveguides divided and drawn to each other in the first and second photomasks, a waveguide pattern for drawing a joint region in which a width of each waveguide changes as the each waveguide goes toward an outer peripheral portion is formed in each of the first and second photomasks, wherein
- the first and second photomasks are overlapped and exposed so that the joint regions of the first and second photomasks are adjacent to each other across the boundary of the joint region where the change in the waveguide width begins, and the sides of the joint region where the waveguide width becomes wider are located on opposite sides of the boundary, thereby connecting the waveguides in the first and second photomasks to each other.
A method of manufacturing an optical waveguide with a photomask in which a waveguide pattern of an optical circuit is divided into a plurality of regions and drawn, the photomask including two photomasks, the method comprising:
- overlapping and exposing the two photomasks so that the joint regions of the two photomasks are adjacent to each other across the boundary of the joint region where the change in the waveguide width begins, and the sides of the joint region where the waveguide width becomes wider are located on opposite sides of the boundary, thereby connecting the waveguides to each other.
Dependencies are inferred from the claim text.