# US 2018/0024410 A1 · Optical modulator and method of manufacturing same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0024410 A1 - Document ID: US20180024410A1 - Status: Published application - Kind: A1 - Application number: 15/548,687 - Filed: 2016-02-02 - Published: 2018-01-25 - Earliest claimed: 2015-02-06 - Assignees: Photonics Electronics Technology Reserach Association; The University of Tokyo - Applicants: Photonics Electronics Technology Reserach Association; The University of Tokyo - Inventors: Junichi FUJIKATA; Shigeki TAKAHASHI; Mitsuru TAKENAKA; Younghyun KIM - Web page: https://patentgrep.com/patent/US20180024410A1 ## CPC - G02F 1/015: based on semiconductor elements having potential barriers, e.g. having a PN or PIN junction (G02F1/03 takes precedence) - G02F 1/025: in an optical waveguide structure (G02F1/017, {G02F1/2257} take precedence) - G02F 1/225: in an optical waveguide structure - G02B 6/12: of the integrated circuit kind (electric integrated circuits H10B, H10D84/00 - H10D89/00, H10F19/00, H10F39/00, H10H29/00, H10K19/00, H10K39/00, H10K59/00, H10N19/00, H10N39/00, H10N59/00, H10N69/00, H10N79/00, H10N89/00) - G02B 6/122: Basic optical elements, e.g. light-guiding paths - G02F 1/0151: {modulating the refractive index} - G02F 1/212: {Mach-Zehnder type} - G02F 2201/12: electrode - G02F 2202/10: semiconductor - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An optical phase modulator 100 according to an embodiment of this disclosure comprises a rib-type waveguide structure 110 comprising: a PN junction 106 comprising Si and formed in a lateral direction on a substrate; and a Si1-xGex layer 108 that is doped with a p-type impurity and comprises at least one layer laminated on the PN junction 106, so as to be electrically connected to the PN junction 106. ## Claims ### Claim 1 An optical phase modulator comprising a rib-type waveguide structure, wherein the rib-type waveguide structure comprises: a PN junction or a PIN junction that comprises Si or Si1-yGey and is formed in a lateral direction on a substrate; and a Si1-xGex layer that comprises at least one layer, is doped by an impurity to exhibit a first conductivity type or a second conductivity type, and is stacked on the PN junction or the PIN junction to be electrically connected to the PN junction or the PIN junction. ### Claim 2 (depends on 1) The optical phase modulator according to claim 1, comprising: a first electrode of the first conductivity type and a second electrode of the second conductivity type that are adjacent to the rib-type waveguide structure, wherein carrier density in the rib-type waveguide structure is changed by application of a voltage to the first electrode and the second electrode. ### Claim 3 (depends on 1) The optical phase modulator according to claim 1, wherein the Si1-xGex layer comprising at least one layer has a lattice strain. ### Claim 4 (depends on 1) The optical phase modulator according to claim 1, wherein the PN junction or the PIN junction formed in the lateral direction on the substrate comprises a layered structure comprising a PN junction or a PIN junction comprising Si and a PN junction or a PIN junction comprising Si1-yGey. ### Claim 5 (depends on 4) The optical phase modulator according to claim 4, wherein the PN junction or the PIN junction, which comprises the layered structure of Si and Si1-yGey that is formed in the lateral direction on the substrate, comprises a rib-type waveguide structure. ### Claim 6 (depends on 1) The optical phase modulator according to claim 1, wherein the Si1-xGex layer comprising at last one layer comprises: a Si1-x1Gex1 layer stacked on the PN junction or the PIN junction; and a Si1-x2Gex2 layer stacked on the Si1-x1Gex1 layer, wherein x2 is smaller than x1. ### Claim 7 (depends on 1) The optical phase modulator according to claim 1, wherein the Si1-xGex layer comprising at last one layer comprises a strain induction film formed above the Si1-xGex layer or on a side of the Si1-xGex layer. ### Claim 8 (depends on 1) The optical phase modulator according to claim 1, wherein, in the PN junction or the PIN junction formed in the lateral direction on the substrate, or in the Si1-xGex layer comprising at last one layer and stacked on the PN junction or the PIN junction to be electrically connected to the PN junction or the PIN junction, doping concentration of the first conductivity type is lower than doping concentration of the second conductivity type. ### Claim 9 (depends on 8) The optical phase modulator according to claim 8, wherein the first conductivity type is a p type, and the second conductivity type is an n type. ### Claim 10 (depends on 1) The optical phase modulator according to claim 1, wherein the PN junction or the PIN junction comprises a plurality of PN junctions or a plurality of PIN junctions that are formed in a periodic manner or an aperiodic manner along a direction of propagation of light. ### Claim 11 (depends on 10) The optical phase modulator according to claim 10, wherein, corresponding to junction positions of the plurality of PN junctions or the plurality of PIN junctions that are formed in a periodic manner or an aperiodic manner, a conductivity type of the Si1-xGex layer comprising at least one layer stacked on the PN junction or the PIN junction changes, in an alternating manner, between the first conductivity type and the second conductivity type. ### Claim 12 (depends on 1) An optical intensity modulator comprises the optical phase modulator according to claim 1. ### Claim 13 A method for manufacturing an optical phase modulator, comprising: forming a PN junction or a PIN junction that comprises Si or Si1-yGey and is formed in a lateral direction; doping regions adjacent to the PN junction or the PIN junction with a first conductivity type and a second conductivity type to form a first electrode of a first conductivity type and a second electrode of a second conductivity type; and forming, on the PN junction or the PIN junction, an Si1-xGex layer that comprises at least one layer, is doped by an impurity to exhibit the first conductivity type or the second conductivity type, and is electrically connected to the PN junction or the PIN junction. ### Claim 14 (depends on 13) The method for manufacturing the optical phase modulator according to claim 13, wherein the forming the Si1-xGex layer comprising at least one layer comprises forming a concavity in the PN junction or the PIN junction and forming an Si1-xGex layer comprising at least one layer on the concavity.