# US 2013/0156370 A1 · Optical coupling devices and silicon photonics chips having the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156370 A1 - Document ID: US20130156370A1 - Status: Published application - Kind: A1 - Application number: 13/620,560 - Filed: 2012-09-14 - Published: 2013-06-20 - Earliest claimed: 2011-12-16 - Assignees: Electronics and Telecommunications Research Institute - Inventors: Do Won Kim; Gyungock Kim - Web page: https://patentgrep.com/patent/US20130156370A1 ## CPC - G02B 6/305: {and having an integrated mode-size expanding section, e.g. tapered waveguide} - G02B 6/1228: {Tapered waveguides, e.g. integrated spot-size transformers (for coupling with fibres G02B6/305)} - G02B 2006/12061: {Silicon} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract Provided are optical coupling devices and silicon photonics chips having the same. the optical coupling device may include a lower layer having a first region and a second region, a first core layer disposed on the lower layer, the first core layer including first and second waveguides disposed on the first and second regions, respectively, a clad layer covering the first waveguide, and a second core layer interposed between the clad layer and the lower layer to cover the second waveguide. The second waveguide has a width decreasing with increasing distance from the first region and a vertical thickness greater than that of the first waveguide. ## Claims ### Claim 1 An optical coupling device, comprising: a lower layer having a first region and a second region; a first core layer disposed on the lower layer, the first core layer including first and second waveguides disposed on the first and second regions, respectively; a clad layer covering the first waveguide; and a second core layer interposed between the clad layer and the lower layer to cover the second waveguide, wherein the second waveguide has a width decreasing with increasing distance from the first region and a vertical thickness greater than that of the first waveguide. ### Claim 2 (depends on 1) The device of claim 1, wherein the first core layer further comprises a slab portion provided at both sides of the first waveguide to cover the first region of the lower layer. ### Claim 3 (depends on 2) The device of claim 2, wherein a difference in height between top surfaces of the first waveguide and the slab portion is smaller than the vertical thickness of the second waveguide. ### Claim 4 (depends on 1) The device of claim 1, wherein the slab portion is formed to expose the second region of the lower layer. ### Claim 5 (depends on 1) The device of claim 1, wherein the second waveguide is formed to have a tapered structure, thereby including a tip spaced apart from the first waveguide, and the tip of the second waveguide is covered with the second core layer. ### Claim 6 (depends on 1) The device of claim 1, wherein the second core layer comprises an outer surface facing an external optical fiber provided at the outside thereof, and the outer surface of the second core layer has an area corresponding to that of a core of the external optical fiber. ### Claim 7 (depends on 6) The device of claim 6, wherein a horizontal width of the second core layer is substantially uniform, when measured along a direction of a longitudinal axis of the second waveguide direction. ### Claim 8 (depends on 6) The device of claim 6, wherein a horizontal width of the second core layer decreases with decreasing distance from the first waveguide, when measured along a direction of a longitudinal axis of the second waveguide direction. ### Claim 9 (depends on 6) The device of claim 6, wherein the second waveguide comprises a tip spaced apart from the outer surface of the second core layer and the first waveguide. ### Claim 10 (depends on 1) The device of claim 1, wherein the first core layer is formed of silicon, the second core layer is formed of a material having a refractive index smaller than that of the first core layer, and the clad layer is formed of a material having a refractive index smaller than that of the second core layer. ### Claim 11 An optical coupling device, comprising: a first core layer including first and second waveguides; a clad layer covering the first waveguide; and a second core layer covering the second waveguide, wherein the second waveguide has a width decreasing with increasing distance from the first waveguide and a vertical thickness greater than that of the first waveguide, and the second core layer comprises a reflecting surface slantingly provided on a longitudinal axis of the second waveguide. ### Claim 12 (depends on 11) The device of claim 11, wherein the reflecting surface of the second core layer has a slanting angle selected to change a propagation direction of an incident light from a direction parallel to the second waveguide to a direction substantially perpendicular to a top surface of the clad layer. ### Claim 13 (depends on 11) The device of claim 11, further comprising a reflecting element formed of a material having a high reflectance to cover the reflecting surface. ### Claim 14 (depends on 11) The device of claim 11, wherein the second core layer is formed to define a slit, the slit is formed to be inclined to a top surface of the second core layer, and one surface of the slit serves as the reflecting surface. ### Claim 15 (depends on 11) The device of claim 11, further comprising, a lower layer provided below the first and second core layers, wherein the second core layer comprises first and second portions attached to the lower layer at both sides of the slit, respectively, and a relative disposition between the first and second portions is fixed by the lower layer. ### Claim 16 A silicon photonics chip, comprising: at least one optical device; a first waveguide connected to the optical device; a second waveguide extending from the first waveguide; a clad layer provided on the first and second waveguides; and a third waveguide interposed between the clad layer and the second waveguide to cover the second waveguide, the clad layer is formed of a material having a refractive index smaller than that of the first and second waveguides, and the third waveguide is formed of a material having a refractive index smaller than that of the second waveguide and greater than that of the clad layer, the second waveguide has a width decreasing with increasing distance from the first waveguide and a vertical thickness greater than that of the first waveguide. ### Claim 17 (depends on 16) The silicon photonics chip of claim 16, further comprising, a slab waveguide covering partially both sidewalls of the first waveguide, wherein a difference in height between top surfaces of the first and slab waveguides is smaller than the vertical thickness of the second waveguide. ### Claim 18 (depends on 16) The silicon photonics chip of claim 16, wherein the third waveguide comprises a reflecting surface provided on a longitudinal axis of the second waveguide, and the reflecting surface is formed to be inclined to the longitudinal axis of the second waveguide. ### Claim 19 (depends on 18) The silicon photonics chip of claim 18, further comprising a reflecting element formed of a material having high reflectance to cover the reflecting surface.