# US 8,542,954 B2 · Optical component having reduced dependency on etch depth > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,954 B2 - Document ID: US8542954B2 - Status: Granted - Kind: B2 - Application number: 13/385,099 - Filed: 2012-02-01 - Published: 2013-08-01 - Granted: 2013-09-24 - Earliest claimed: 2012-02-01 - Assignees: Kotura, Inc. - Applicants: Cheng-Chih Kung; Shirong Liao - Inventors: Cheng-Chih Kung; Shirong Liao - Web page: https://patentgrep.com/patent/US8542954B2 ## CPC - G02B 6/134: by substitution by dopant atoms - B82Y 20/00: Nanooptics, e.g. quantum optics or photonic crystals - G02B 6/1223: {high refractive index type, i.e. high-contrast waveguides} - H10F 30/223: the potential barrier being a PIN barrier - G02B 2006/12061: {Silicon} - G02B 2006/12142: {Modulator} - G02B 2006/12176: {Etching} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract An optical device includes an active component on a base. The active component is a light sensor and/or a light modulator. The active component is configured to guide a light signal through a ridge of an active medium extending upwards from slab regions of the active medium. The slab regions are on opposing sides of the ridge. The active medium includes a doped region that extends into a lateral side of the ridge and also into one of the slab regions. The depth that the doped region extends into the slab region is further than the depth that the doped region extends into the ridge. ## Claims ### Claim 1 An optical device, comprising: an active component on a base and having at least one functionality selected from a group consisting of light sensor functionality and light modulator functionality, the active component configured to guide the light signal through a ridge of an active medium extending upwards from slab regions of the active medium, the slab regions being on opposing sides of the ridge, the active medium including a doped region extending into a lateral side of the ridge and also into one of the slab regions of the active medium, and a depth that the doped region extends into the slab region being further than a depth that the doped region extends into the ridge. ### Claim 2 (depends on 1) The device of claim 1, wherein the active component has a thickness ratio greater than 1:1, the thickness ratio being a ratio of the depth that the doped region extends into the slab region: the depth that the doped region extends into the ridge. ### Claim 3 (depends on 1) The device of claim 1, wherein multiple doped zones combine to form the doped region. ### Claim 4 (depends on 3) The device of claim 3, wherein a first one of the doped zones is present in the slab region of the active medium without being present in the ridge of the active medium. ### Claim 5 (depends on 3) The device of claim 3, wherein a second one of the doped zones is present in the ridge of the active medium and also in one of the slab regions of the active medium. ### Claim 6 (depends on 3) The device of claim 3, wherein a first one of the doped zone and a second one of the doped zone combine to form the doped region, the first doped zone being present in the slab region of the active medium without being present in the ridge of the active medium and the second doped zone being present in both the ridge of the active medium and also in one of the slab regions of the active medium. ### Claim 7 (depends on 6) The device of claim 6, wherein at least a portion of the first doped zone is located between the base and a portion of the second doped zone that is contacted by the first doped zone. ### Claim 8 (depends on 7) The device of claim 7, wherein the first doped zone is not located under the ridge. ### Claim 9 (depends on 7) The device of claim 7, further comprising: an electrical contact in contact with the second doped zone. ### Claim 10 (depends on 1) The device of claim 1, wherein the active medium is selected from a group consisting of germanium and silicon-germanium. ### Claim 11 (depends on 1) The device of claim 1, further comprising: electronics configured to apply electrical energy to the doped regions so as to form an electrical field in the ridge of the active medium. ### Claim 12 (depends on 1) The device of claim 1, wherein the doped region is one a plurality of doped regions included on the active component and at least two of the doped regions are located in the slab regions on opposing sides of the ridge. ### Claim 13 (depends on 1) The device of claim 1, further comprising: a waveguide on the base and configured to guide the light signal through a light-transmitting medium, the active component positioned such that the ridge of active medium receives the light signal from the waveguide. ### Claim 14 A method of forming an optical device comprising: generating a device precursor having a precursor for an active component for providing at least one functionality selected from a group consisting of light sensor functionality and light modulator functionality, the active component precursor having a ridge of an active medium extending upwards from slab regions of the active medium, the slab regions being on opposing sides of the ridge; and forming a doped region that extends into a lateral side of the ridge and also into one of the slab regions of the active medium such that a depth that the doped region extends into the slab region is further than a depth that the doped region extends into the ridge. ### Claim 15 (depends on 14) The method of claim 14, wherein forming the doped region includes forming a first doped zone and a second doped zone such that the first doped zone and the second doped zone combine to form the doped region. ### Claim 16 (depends on 15) The method of claim 15, wherein the first doped zone is present in the slab region of the active medium without being present in the ridge of the active medium. ### Claim 17 (depends on 15) The method of claim 15, wherein the second doped zones is present in the ridge of the active medium and also in one of the slab regions of the active medium. ### Claim 18 (depends on 15) The method of claim 15, wherein the first doped zone is present in the slab region of the active medium without being present in the ridge of the active medium and the second doped zone is present in both the ridge of the active medium and also in one of the slab regions of the active medium. ### Claim 19 (depends on 18) The method of claim 18, wherein at least a portion of the first doped zone is located between the base and a portion of the second doped zone that is contacted by the first doped zone. ### Claim 20 (depends on 19) The method of claim 19, wherein the first doped zone is not located under the ridge.