# US 2023/0273370 A1 · Optical isolator integrated with optical devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0273370 A1 - Document ID: US20230273370A1 - Status: Published application - Kind: A1 - Application number: 17/866,335 - Filed: 2022-07-15 - Published: 2023-08-31 - Earliest claimed: 2022-02-25 - Assignees: Taiwan Semiconductor Manufacturing Company, Ltd. - Applicants: Taiwan Semiconductor Manufacturing Co., Ltd. - Inventors: Cheng-Tse TANG; Chewn-Pu JOU - Web page: https://patentgrep.com/patent/US20230273370A1 ## CPC - G02B 6/124: Geodesic lenses or integrated gratings - G02B 6/125: Bends, branchings or intersections - G02B 6/12007: {forming wavelength selective elements, e.g. multiplexer, demultiplexer} - G02B 6/12011: {characterised by the arrayed waveguides, e.g. comprising a filled groove in the array section} - G02B 6/136: by etching - G02B 6/34: utilising prism or grating {(G02B6/293 takes precedence)} - G02B 2006/12107: {Grating} - G02B 2006/12126: {Light absorber} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A device includes an optical isolator disposed between adjacent optical waveguides along a direction. The optical isolator has vertical or horizontal dimensions that are different than at least one of the optical waveguides. The vertical and horizontal dimensions are greater than vertical and horizontal dimensions of at least one of the waveguides. In various embodiments, the structure of the optical isolator can be a planar structure, a columnar periodic structure, or a grating structure. The material of the optical isolator can be a metallic material or a dielectric material. In some embodiments, the optical isolator and the optical waveguides are used to enhance the performance of an optical multiplexing device. ## Claims ### Claim 1 A device, comprising: a first waveguide having a first length extending along a first direction, a first width extending along a second direction that is orthogonal to the first direction, and a first height extending along a third direction that is orthogonal to the first and second directions; a second waveguide aligned with the first waveguide along the first direction, the second waveguide having a second length extending along the first direction, a second width extending along the second direction, and a second height extending along the third direction, the second length of the second waveguide entirely overlapping the first length of the first waveguide along the second direction; and an optical isolator between the first waveguide and the second waveguide, the optical isolator having a third length extending along the first direction, a third width extending along the second direction, and a third height extending along the third direction, the third height being greater than at least one of the first height or the second height, the optical isolator being formed of a material that is different from a material of the first waveguide or a material of the second waveguide. ### Claim 2 (depends on 1) The device in claim 1, wherein the third length is greater than the first length and the second length, and the third width is less than at least one of the first width or the second width. ### Claim 3 (depends on 1) The device in claim 1, wherein the isolator is a discrete periodic structure of a plurality of rods, the discrete periodic structure extending along the first direction. ### Claim 4 (depends on 3) The device in claim 3, wherein the plurality of rods has a circular cross-sectional shape and a dimension of the plurality of rods is same for each of the plurality of rods. ### Claim 5 (depends on 3) The device in claim 3, wherein the plurality of rods includes a first plurality of rods that has a first cross-sectional shape and a second plurality of rods that has a second cross-section shape, the first cross-section shape being different than the second cross-sectional shape. ### Claim 6 (depends on 1) The device in claim 1, wherein the isolator is a grating periodic structure extending along the first direction and including a plurality of interconnected columnar structures. ### Claim 7 (depends on 6) The device in claim 6, wherein the plurality of interconnected columnar structures includes a first plurality of columns and a second plurality of joints, each of the first plurality of columns contacts nearest adjacent ones of the second plurality of joints along the first direction, wherein a width of the second plurality of joints along the second direction is less than a width of the first plurality of columns along the second direction. ### Claim 8 (depends on 6) The device in claim 6, wherein the grating periodic structure has a surface that is undulating. ### Claim 9 (depends on 3) The device in claim 3, wherein the discrete periodic structure includes a plurality of rods distributed in the first direction and the second direction. ### Claim 10 (depends on 9) The device in claim 9, wherein the distribution of the rods in the second direction comprising multiple arrays, wherein a dimension of the rod in the arrays closer to the first and second waveguides is less than a dimension of the rods in the central array. ### Claim 11 (depends on 1) The device in claim 1, wherein the isolator includes a metallic material, and an inter-metal dielectric (IMD) surrounds the isolator and the first and second waveguides. ### Claim 12 (depends on 1) The device in claim 1, wherein the isolator includes a dielectric material. ### Claim 13 A method, comprising: forming a first waveguide having a first length extending along a first direction, a first width extending along a second direction that is orthogonal to the first direction, and a first height extending along a third direction that is orthogonal to the first and second directions; forming a second waveguide aligned with the first waveguide along the first direction, the second waveguide having a second length extending along the first direction, a second width extending along the second direction, and a second height extending along the third direction, the second length of the second waveguide entirely overlapping the first length of the first waveguide along the second direction; and forming an optical isolator between the first waveguide and the second waveguide, the optical isolator having a third length extending along the first direction, a third width extending along the second direction, and a third height extending along the third direction, the third height being greater than at least one of the first height or the second height, the optical isolator being formed of a material that is different from a material of the first waveguide or a material of the second waveguide. ### Claim 14 (depends on 13) The method of claim 13, wherein the third length is greater than the first length and the second length, and the third width is less than at least one of the first width or the second width. ### Claim 15 (depends on 13) The method of claim 13, wherein the isolator is a discrete periodic structure, and the discrete periodic structure includes a plurality of rods extending along the first direction. ### Claim 16 (depends on 13) The method of claim 13, wherein the isolator is a grating periodic structure extending along the first direction and including a plurality of interconnected columnar structures. ### Claim 17 A multiplexing device, comprising: a first waveguide having a first length extending along a first direction, a first width extending along a second direction that is orthogonal to the first direction, and a first height extending along a third direction that is orthogonal to the first and second directions; a second waveguide aligned with the first waveguide along the first direction, the second waveguide having a second length extending along the first direction, a second width extending along the second direction, and a second height extending along the third direction, the second length of the second waveguide being greater than the first length of the first waveguide; and an optical isolator being partially positioned between the first waveguide and the second waveguide, the optical isolator having a third length extending along the first direction, a third width extending along the second direction, and a third height extending along the third direction, the third height being greater than at least one of the first height or the second height, the optical isolator being formed of a material that is different from a material of the first waveguide or a material of the second waveguide. ### Claim 18 (depends on 18) The multiplexing device of claim 18, wherein a wave passing through the first waveguide has a first phase corresponding to the first length, a wave passing through the second waveguide has a second phase corresponding to the second length, and a difference between the first and second phases is corresponding to the difference between the first length of the first waveguide and the second length of the second waveguide. ### Claim 19 (depends on 18) The multiplexing device of claim 18, wherein the isolator includes a first metallic layer adjacent to the first waveguide along the second direction, and a second metallic layer adjacent to the second waveguide along the second direction. ### Claim 20 (depends on 18) The multiplexing device of claim 18, wherein the isolator is absent from portions of a space between the first and second waveguides to reduce optical isolation in that portions.