# US 10,313,023 B2 · Quantum communication component, receiver and system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,313,023 B2 - Document ID: US10313023B2 - Status: Granted - Kind: B2 - Application number: 15/903,574 - Filed: 2018-02-23 - Published: 2019-01-10 - Granted: 2019-06-04 - Earliest claimed: 2017-07-10 - Assignees: Kabushiki Kaisha Toshiba - Applicants: Kabushiki Kaisha Toshiba - Inventors: Taofiq Paraiso; Marco Lucamarini; Zhiliang Yuan; Andrew James Shields - Web page: https://patentgrep.com/patent/US10313023B2 ## CPC - H04B 10/70: Photonic quantum communication - G02B 6/12002: {Three-dimensional structures} - G02B 6/12004: {Combinations of two or more optical elements} - G02B 6/12007: {forming wavelength selective elements, e.g. multiplexer, demultiplexer} - G02B 6/13: Integrated optical circuits characterised by the manufacturing method - G02F 1/225: in an optical waveguide structure - H04L 9/0852: {Quantum cryptography (transmission systems employing electromagnetic waves other than radio waves, e.g. light, infrared H04B10/00; wavelength-division multiplex systems H04J14/02; WDM arrangements H04J14/03)} - G02B 6/12009: {comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides} - G02F 1/212: {Mach-Zehnder type} - G02F 2201/06: integrated waveguide - G02F 2201/14: asymmetric - G02F 2201/58: Arrangements comprising a monitoring photodetector - G02F 2203/50: Phase-only modulation - H04B: TRANSMISSION - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - 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 - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A component for a quantum communication system, the component comprising: an input section and a decoder section, the input section comprising n waveguides, where n is an integer of at least 2, the decoder section comprising m decoders, where m is an integer of at least 2, each decoder comprising at least one waveguide, the input section and the decoder section being provided on a single substrate such that the waveguides are continuous and integrated between the input section and the decoder section, the waveguides of the input section and the decoder section being arranged such that light pulses enter the waveguides of the decoder section via the waveguides of the input section and the m decoders operate in parallel. ## Claims ### Claim 1 A component for a quantum communication system, the component comprising: an input section and a decoder section, the input section comprising n waveguides, where n is an integer of at least 2, the decoder section comprising m decoders, where m is an integer of at least 2, each decoder comprising at least one waveguide, the input section and the decoder section being provided on a single substrate such that the waveguides are continuous and integrated between the input section and the decoder section, the waveguides of the input section and the decoder section being arranged such that light pulses enter the waveguides of the decoder section via the waveguides of the input section and the m decoders operate in parallel. ### Claim 2 (depends on 1) A component according to claim 1, the component further comprising an output section, the output section comprising p waveguides, where p is an integer of at least 2, the output section and the decoder section being provided on a single substrate such that the waveguides are continuous and integrated between the output section and the decoder section. ### Claim 3 (depends on 2) A component according to claim 2, the component further comprising a router section, the router section comprising q waveguides, where q is an integer of at least 2, the router section and the input section being provided on a single substrate such that the waveguides are continuous and integrated between the outer section and the input section. ### Claim 4 (depends on 2) A component according to claim 2, wherein the substrate is a passive material. ### Claim 5 (depends on 2) A component according to claim 2, wherein the substrate is selected from Si, SOI (silicon on insulator), SiN (silicon nitride), SiO2 (silicon dioxide), SiON (Silicon Oxynitride), glasses, polymers, diamond or silicon carbide. ### Claim 6 (depends on 2) A component according to claim 2, wherein at least one decoder of the decoding section comprises an asymmetric Mach-Zehnder Interferometer (AMZI), said AMZI comprising at least two of said waveguides. ### Claim 7 (depends on 6) A component according to claim 6, wherein the AMZI comprises a phase modulator. ### Claim 8 (depends on 7) A component according to claim 7, wherein the AMZI comprises an electrode provided over a part of one of the two of said waveguides comprised in the AMZI. ### Claim 9 (depends on 2) A component according to claim 2, wherein the decoder section comprises a first decoder and a second decoder out of the plurality of m decoders, the first decoder being adapted to decode using a first measurement basis and the second decoder being adapted to decode using a second measurement basis, different from the first measurement basis, the waveguides of the input section being configured to randomly direct photons to the first decoder or the second decoder using a passive switching arrangement. ### Claim 10 (depends on 9) A component according to claim 9, wherein the passive switching arrangement comprises a coupler with a least two outputs, the coupler being a passive coupler whereby a photon entering the coupler randomly exits the coupler through one of the at least two outputs. ### Claim 11 (depends on 2) A component according to claim 2, wherein the parallel decoding is adapted to provide parallel decoding using at least two protocols. ### Claim 12 (depends on 11) A component according to claim 11, wherein the protocols are selected from BB84, B92, COW, DPS, RFI and 6 state BB84. ### Claim 13 (depends on 11) A component according to claim 11, wherein each decoder comprises a plurality elements, said elements comprising said waveguides and wherein different protocols are realised by combining different elements from different decoders. ### Claim 14 (depends on 2) A component according to claim 2, wherein the input section is adapted to direct light pulses into two or more decoders. ### Claim 15 (depends on 14) A component according to claim 14, wherein the input section comprises a wavelength division multiplexer adapted to send the input light pulses to different decoders depending on the wavelengths of the light pulses. ### Claim 16 (depends on 2) A component according to claim 2, wherein the output section comprises detectors. ### Claim 17 (depends on 2) A receiver for a quantum communication system, the receiver comprising a component according to claim 2. ### Claim 18 (depends on 17) A quantum communication system comprising an emitter and a receiver according to claim 17. ### Claim 19 A method of fabricating a component, said method comprising: providing a substrate; forming a cladding layer on said substrate; forming a waveguide layer on said cladding layer; patterning said waveguide layer; and forming a cladding layer overlying said waveguide layer, wherein patterning said waveguide layer comprises: patterning an input section and a decoder section to form a plurality of waveguides, the input section comprising comprises n waveguides, where n is an integer of at least 2, the decoder section comprising m decoders, where m is an integer of at least 2, each decoder comprising at least one waveguide, the input section and the decoder section being provided on the said substrate such that the waveguides are continuous and integrated between the input section and the decoder section, the waveguides of the input section and the decoder section being arranged such that light pulses enter the waveguides of the decoder section via the waveguides of the input section and the m decoders operate in parallel.