# US 10,120,133 B2 · Edge construction on optical devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,120,133 B2 - Document ID: US10120133B2 - Status: Granted - Kind: B2 - Application number: 14/974,515 - Filed: 2015-12-18 - Published: 2017-06-22 - Granted: 2018-11-06 - Earliest claimed: 2015-12-18 - Assignees: Mellanox Technologies Silicon Photonics Inc. - Applicants: Kotura, Inc. - Inventors: Scott Benjamin Golper; William Dos Santos Fegadolli; Arin Abed - Web page: https://patentgrep.com/patent/US10120133B2 ## CPC - G02B 6/136: by etching - G02B 6/122: Basic optical elements, e.g. light-guiding paths - G02B 6/30: for use between fibre and thin-film device - H10P 54/00: Cutting or separating of wafers, substrates or parts of devices - G02B 2006/12092: {Stepped} - G02B 2006/12097: {Ridge, rib or the like} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A method of forming an optical device includes obtaining a wafer having multiple optical device dies that each includes a waveguide. The method also includes forming a facet on the waveguide of different dies. The method further includes separating the dies from the wafer after forming the facets. The dies are separated from the wafer such that the facets are positioned at an edge of the dies. ## Claims ### Claim 1 A method of forming an optical device, comprising: obtaining a wafer having multiple optical device dies that each includes a waveguide; forming a facet on the waveguide of different dies; and separating the dies from the wafer after forming the facets, the dies being separated from the wafer such that the facets are positioned at an edge of the dies, and separating the dies forms an edge wall at a lateral side of at least one of the dies such that the edge wall has a displacement distance of less than 2 μm from the facet, the displacement distance being the shortest distance that the waveguide on the at least one die can moved laterally before a portion of the waveguide is aligned with the edge wall. ### Claim 2 (depends on 1) The method of claim 1, wherein forming the facet includes etching the facet. ### Claim 3 (depends on 2) The method of claim 2, wherein etching the facet provides the facet with a roughness less than 20 nm. ### Claim 4 (depends on 1) The method of claim 1, wherein separating the dies includes dicing the wafer. ### Claim 5 (depends on 1) The method of claim 1, further comprising: forming an anti-reflective coating over the facets before separating the dies. ### Claim 6 (depends on 1) The method of claim 1, further comprising: forming a recess between adjacent dies after forming the facets and before separating the dies. ### Claim 7 (depends on 6) The method of claim 6, wherein the wafers includes a light-transmitting medium on a base, the waveguide is configured to guide a light signal through the light-transmitting medium, and the recess extends at least 10 μm into the base. ### Claim 8 (depends on 6) The method of claim 6, wherein the dies are separated such that a portion of a bottom of the recess becomes a shelf extending outward from at least one of the separated dies. ### Claim 9 (depends on 1) The method of claim 1, further comprising: attaching an optical fiber to one of the separated dies such that the optical fiber is optically aligned with the facet. ### Claim 10 (depends on 9) The method of claim 9, wherein a facet of the optical fiber is less than 20 μm from the facet on the die. ### Claim 11 (depends on 1) The method of claim 1, wherein at least one of the dies has the facet at a non-perpendicular angle relative to a direction of propagation of light signals through the waveguide at the facet, the facet having the non-perpendicular angle before separating the dies from the wafer. ### Claim 12 (depends on 1) The method of claim 1, wherein at least one of the separated dies is constructed such that the facet is positioned above a facet shelf that extends outward from the facet to a recess wall, a recess shelf extends outwards from the recess wall to an edge wall, the edge wall being an outermost side of the optical device. ### Claim 13 A method of forming an optical device, comprising: obtaining a wafer having multiple optical device dies that each includes a waveguide; forming a facet on the waveguide of different dies; and separating the dies from the wafer after forming the facets, the dies being separated from the wafer such that the facets are positioned at an edge of the dies, at least one of the separated dies is constructed such that the facet is positioned above a facet shelf that extends outward from the facet to a recess wall, a recess shelf extends outwards from the recess wall to an edge wall with the edge wall being an outermost side of the optical device; and attaching an optical fiber to one of the separated dies such that the optical fiber is optically aligned with the facet, the optical fiber being positioned such that an imaginary line can be drawn perpendicular to an end of the optical fiber and through the edge wall. ### Claim 14 (depends on 13) The method of claim 13, wherein separating the dies forms an edge wall at a lateral side of at least one of the dies such that the edge wall has a displacement distance of less than 2 μm from the facet, the displacement distance being the shortest distance that the waveguide on the at least one die can moved laterally before a portion of the waveguide is aligned with the edge wall. ### Claim 15 (depends on 13) The method of claim 13, wherein forming the facet includes etching the facet and etching the facet provides the facet with a roughness less than 20 nm. ### Claim 16 (depends on 13) The method of claim 13, wherein separating the dies includes dicing the wafer. ### Claim 17 (depends on 13) The method of claim 13, further comprising: forming a recess between adjacent dies after forming the facets and before separating the dies. ### Claim 18 (depends on 17) The method of claim 17, wherein the wafers includes a light-transmitting medium on a base, the waveguide is configured to guide a light signal through the light-transmitting medium, and the recess extends at least 10 μm into the base. ### Claim 19 (depends on 17) The method of claim 17, wherein the dies are separated such that a portion of a bottom of the recess becomes a shelf extending outward from at least one of the separated dies. ### Claim 20 (depends on 13) The method of claim 13, wherein a facet of the optical fiber is less than 20 from the facet on the die.