# US 5,349,466 A · Frequency doubler including an electrically controlled optical index network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,349,466 A - Document ID: US5349466A - Status: Granted - Kind: A - Application number: 08/178,359 - Filed: 1994-01-06 - Granted: 1994-09-20 - Earliest claimed: 1991-12-10 - Assignees: Thomson-CSF - Inventors: Dominique Delacourt; Michel Papuchon; Eric Lallier; Florence Armani - Web page: https://patentgrep.com/patent/US5349466A ## CPC - G02F 1/292: {by controlled diffraction or phased-array beam steering (controlled diffraction for optical switching G02F1/31)} - G02F 1/3558: {Poled materials, e.g. with periodic poling; Fabrication of domain inverted structures, e.g. for quasi-phase-matching [QPM]} - G02F 1/37: for second-harmonic generation {(G02F1/3532 takes precedence)} - H01S 3/109: Frequency multiplication, e.g. harmonic generation - H01S 3/115: using intracavity electro-optic devices - G02F 1/3546: {Active phase matching, e.g. by electro- or thermo-optic tuning} - G02F 1/3548: {Quasi phase matching [QPM], e.g. using a periodic domain inverted structure} - 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 - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL ## Abstract The device according to the invention is a frequency doubler comprising an optical index network which can be electrically controlled by two continuous electrodes, the network being created by the presence of (+P) polarization domains periodically separated by (-P) polarization domains, the electrodes being used to electrooptically compensate for variations in the index between the (+P) domains and (-P) domains. ## Claims ### Claim 1 A frequency doubler comprising: a material having a locally reversed ferroelectric polarization to create alternating (+P) domains and (-P) domains; a first continuous electrode formed on the material above the alternating (+P) domains and (-P) domains for inducing an electric field in the alternating (+P) domains and (-P) domains; and a second electrode formed on the material. ### Claim 2 (depends on 1) The frequency doubler according to claim 1, wherein the material is a lithium niobate crystal. ### Claim 3 (depends on 2) The frequency doubler according to claim 2, wherein the ferroelectric polarization reversals are obtained by local diffusion of titanium into faces of the lithium niobate crystal. ### Claim 4 (depends on 1) The frequency doubler according to claim 1, wherein the material is a lithium tantalate crystal. ### Claim 5 (depends on 4) The frequency doubler according to claim 4, wherein the polarization reversals are obtained by proton exchange of L.sub.i + ions. ### Claim 6 (depends on 1) The frequency doubler according to claim 1, wherein the material is KTiOPO.sub.4. ### Claim 7 (depends on 6) The frequency doubler according to claim 6, wherein the polarization reversals are produced by replacing K+ ions by Rb+ ions in the presence of barium oxide. ### Claim 8 (depends on 1) The frequency doubler according to claim 1, wherein the material is a polymer containing intermolecular or intramolecular groups which can be oriented by an electrical field. ### Claim 9 (depends on 8) The frequency doubler according to claim 8, wherein the polarization reversals are obtained by applying an electric field through an interleaved set of electrodes deposited on the surface of the material, this set of electrodes being subsequently deleted and replaced by the first continuous electrode. ### Claim 10 A frequency doubler comprising: a material having a locally reversed ferroelectric polarization to create alternating (+P) domains and (-P) domains; a first continuous electrode formed directly on the material above the alternating (+P) domains and (-P) domains to contact the alternating (+P) domains and (-P) domains; and a second electrode formed on the material. ### Claim 11 (depends on 10) The frequency doubler according to claim 10, wherein the material is a lithium niobate crystal. ### Claim 12 (depends on 11) The frequency doubler according to claim 11, wherein the ferroelectric polarization reversals are obtained by local diffusion of titanium into faces of the lithium niobate crystal. ### Claim 13 (depends on 10) The frequency doubler according to claim 10, wherein the material is a lithium tantalate crystal. ### Claim 14 (depends on 13) The frequency doubler according to claim 13, wherein the polarization reversals are obtained by proton exchange of Li+ ions. ### Claim 15 (depends on 10) The frequency doubler according to claim 10, wherein the material is KTiOPO.sub.4. ### Claim 16 (depends on 15) The frequency doubler according to claim 15, wherein the polarization reversals are produced by replacing K+ ions by Rb+ ions in the presence of barium oxide. ### Claim 17 (depends on 10) The frequency doubler according to claim 10, wherein the material is a polymer containing intermolecular or intramolecular groups which can be oriented by an electrical field. ### Claim 18 (depends on 17) The frequency doubler according to claim 17, wherein the polarization reversals are obtained by applying an electric field through an interleaved set of electrodes deposited on the surface of the material, this set of electrodes being subsequently deleted and replaced by the first continuous electrode. ### Claim 19 A frequency doubler comprising: a material having a locally reversed ferroelectric polarization to create alternating (+P) domains and (-P) domains; a first continuous electrode formed on a first face of the material above the alternating (+P) domains and (-P) domains; and a second electrode formed on the first face of the material, the second electrode being parallel to the first continuous electrode. ### Claim 20 (depends on 19) The frequency doubler according to claim 19, wherein the material is a lithium niobate crystal. ### Claim 21 (depends on 20) The frequency doubler according to claim 20, wherein the ferroelectric polarization reversals are obtained by local diffusion of titanium into faces of the lithium niobate crystal. ### Claim 22 (depends on 19) The frequency doubler according to claim 19, wherein the material is a lithium tantalate crystal. ### Claim 23 (depends on 22) The frequency doubler according to claim 22, wherein the polarization reversals are obtained by proton exchange of Li+ ions. ### Claim 24 (depends on 19) The frequency doubler according to claim 19, wherein the material is KTiOPO.sub.4. ### Claim 25 (depends on 24) The frequency doubler according to claim 24, wherein the polarization reversals are produced by replacing K+ ions by Rb+ ions in the presence of barium oxide. ### Claim 26 (depends on 19) The frequency doubler according to claim 19, wherein the material is a polymer containing intermolecular or intramolecular groups which can be oriented by an electrical field. ### Claim 27 (depends on 26) The frequency doubler according to claim 26, wherein the polarization reversals are obtained by applying an electric field through an interleaved set of electrodes deposited on the surface of the material, this set of electrodes being subsequently deleted and replaced by the first continuous electrode.