# US 12,603,710 B2 · Optical drive for qubits > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,603,710 B2 - Document ID: US12603710B2 - Status: Granted - Kind: B2 - Application number: 18/288,139 - Filed: 2021-04-28 - Published: 2024-06-20 - Granted: 2026-04-14 - Earliest claimed: 2021-04-28 - Assignees: IQM Finland Oy - Applicants: Iqm Finland Oy - Inventors: Pasi Lähteenmäki - Web page: https://patentgrep.com/patent/US12603710B2 ## CPC - G06N 10/00: Quantum computing, i.e. information processing based on quantum-mechanical phenomena - H04B 10/70: Photonic quantum communication - G06N 10/40: Physical realisations or architectures of quantum processors or components for manipulating qubits, e.g. qubit coupling or qubit control - H04B 10/2575: Radio-over-fibre, e.g. radio frequency signal modulated onto an optical carrier - G06N: COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS - H04B: TRANSMISSION ## Abstract Example embodiments relate to delivery of qubit drive signals to a cryogenic environment of a quantum computer. Qubit drive signal(s) may be conveyed to the cryogenic environment as optical signal(s). The optical signal(s) may be transduced to radio frequency signal(s) at the cryogenic environment for driving qubit(s). Apparatuses and methods are disclosed. ## Claims ### Claim 1 An apparatus, comprising: at least one electro-optic modulator configured to modulate at least one optical signal with at least one input radio frequency signal at a non-cryogenic environment of a quantum computer; at least one optical fiber configured to convey the at least one optical signal to a cryogenic environment of the quantum computer; at least one optomechanical transducer configured to transduce the at least one optical signal to at least one radio frequency signal at the cryogenic environment of the quantum computer; and driving circuitry configured to drive at least one qubit of the quantum computer based on the at least one radio frequency signal. ### Claim 2 (depends on 1) The apparatus according to claim 1, further comprising: at least one optical isolator at the non-cryogenic environment of the quantum computer, wherein the at least one optical isolator is located optically between the at least one electro-optic modulator and the at least one optomechanical transducer, and wherein the at least one optical isolator is configured to dissipate energy received from the cryogenic environment. ### Claim 3 (depends on 1) The apparatus according to claim 1, wherein the at least one optical fiber is configured to convey a plurality of optical signals to the cryogenic environment of the quantum computer, the apparatus comprising: a plurality of optomechanical transducers configured to transduce the plurality of optical signals to a plurality of radio frequency signals at the cryogenic environment of the quantum computer, wherein the driving circuitry is configured to drive a plurality of qubits based on the plurality of radio frequency signals. ### Claim 4 (depends on 3) The apparatus according to claim 3, further comprising: a plurality of electro-optical modulators configured to modulate the plurality of optical signals with a plurality of input radio frequency signals at a non-cryogenic environment of the quantum computer. ### Claim 5 (depends on 3) The apparatus according to claim 3, further comprising: a multiplexer configured to multiplex the plurality of optical signals to an optical fiber configured to convey the plurality of optical signals to the cryogenic environment of the quantum computer. ### Claim 6 (depends on 5) The apparatus according to claim 5, further comprising: a demultiplexer configured to demultiplex the plurality of optical signals from the optical fiber at the cryogenic environment of the quantum computer. ### Claim 7 (depends on 6) The apparatus according to claim 6, wherein the multiplexer comprises a wavelength division multiplexer and/or wherein the demultiplexer comprises a wavelength division demultiplexer. ### Claim 8 (depends on 5) The apparatus according to claim 5, further comprising: a plurality of optical isolators at a non-cryogenic environment of the quantum computer, wherein the plurality of optical isolators are located optically between the multiplexer and respective electro-optic modulators, and wherein the plurality of optical isolators are configured to dissipate energy received from the cryogenic environment via the optical fiber. ### Claim 9 A method, comprising: modulating at least one optical signal with at least one input radio frequency signal at a non-cryogenic environment of a quantum computer; conveying the at least one optical signal to a cryogenic environment of the quantum computer; transducing the at least one optical signal to at least one radio frequency signal at the cryogenic environment of the quantum computer; and driving at least one qubit based on the at least one radio frequency signal. ### Claim 10 (depends on 9) The method according to claim 9, further comprising: transducing the at least one optical signal to the at least one radio frequency signal by at least one optomechanical transducer at the cryogenic environment of the quantum computer. ### Claim 11 (depends on 9) The method according to claim 9, further comprising: modulating the at least one optical signal with the at least one input radio frequency signal by at least one electro-optic modulator. ### Claim 12 (depends on 11) The method according to claim 11, further comprising: providing at least one optical isolator at the non-cryogenic environment of the quantum computer, wherein the at least one optical isolator is provided optically between the at least one electro-optic modulator and at least one optomechanical transducer for dissipating energy received from the cryogenic environment. ### Claim 13 (depends on 9) The method according to claim 9, further comprising: conveying a plurality of optical signals to the cryogenic environment of the quantum computer; transducing the plurality of optical signals to a plurality of radio frequency signals at the cryogenic environment of the quantum computer; and driving a plurality of qubits based on the plurality of radio frequency signals. ### Claim 14 (depends on 13) The method according to claim 13, further comprising: modulating the plurality of optical signals with a plurality of input radio frequency signals at non-cryogenic environment of the quantum computer. ### Claim 15 (depends on 13) The method according to claim 13, further comprising: multiplexing, by a multiplexer, the plurality of optical signals to an optical fiber configured to convey the plurality of optical signals to the cryogenic environment of the quantum computer. ### Claim 16 (depends on 15) The method according to claim 15, further comprising: demultiplexing, by a demultiplexer, the plurality of optical signals from the optical fiber at the cryogenic environment of the quantum computer. ### Claim 17 (depends on 16) The method according to claim 16, wherein the multiplexer comprises a wavelength division multiplexer and/or wherein the demultiplexer comprises a wavelength division demultiplexer. ### Claim 18 (depends on 15) The method according to claim 15, further comprising: providing a plurality of optical isolators at non-cryogenic environment of the quantum computer, wherein the plurality of optical isolators are provided optically between the multiplexer and respective electro-optic modulators for dissipating energy received from the cryogenic environment via the optical fiber.