# US 5,706,114 A · Polyhedral integrated and free space optical interconnection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,706,114 A - Document ID: US5706114A - Status: Granted - Kind: A - Application number: 08/538,683 - Filed: 1995-10-03 - Granted: 1998-01-06 - Earliest claimed: 1995-10-03 - Inventors: Ireena A. Erteza - Web page: https://patentgrep.com/patent/US5706114A ## CPC - H04B 10/11: Arrangements specific to free-space transmission, i.e. transmission through air or vacuum - H04B: TRANSMISSION ## Abstract An optical communication system uses holographic optical elements to provide guided wave and non-guided communication, resulting in high bandwidth, high connectivity optical communications. Holograms within holographic optical elements route optical signals between elements and between nodes connected to elements. Angular and wavelength multiplexing allow the elements to provide high connectivity. The combination of guided and non-guided communication allows compact polyhedral system geometries. Guided wave communications provided by multiplexed substrate-mode holographic optical elements eases system alignment. ## Claims ### Claim 1 An apparatus to route the output of a first optical transmitter node to a first optical receiver node, comprising: a) a plurality of substantially planar optically transmissive plates disposed in an arrangement where at least some of the plates are not parallel with each other; b) inter-facet means for communicating optical signals among the plates; c) a first holographic optical element mounted with a first plate and having a first hologram that directs optical signals from the first optical transmitter node to the inter-facet means; and d) a second holographic optical element mounted with a second plate and having a second hologram that directs optical signals from the inter-facet means to the first optical receiver node, wherein the inter-facet means comprises a third holographic optical element containing a third hologram and mounted with the first plate and a fourth holographic optical element containing a fourth hologram and mounted with the second plate; wherein the third hologram directs optical signals from the first holographic optical element to the fourth holographic optical element, and the fourth hologram directs optical signals from the third holographic optical element to the second holographic optical element. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein the first and second holograms comprise transmissive holograms. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein the first, second, third, and fourth holograms comprise transmissive holograms. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the arrangement defines a space with known refractive properties between the plates. ### Claim 5 (depends on 1) The apparatus of claim 1, further comprising a second receiver mounted with the first plate and means for directing optical information from the first transmitter to the second receiver. ### Claim 6 An apparatus to route the output of a first optical transmitter node to a first optical receiver node, comprising: a) a plurality of substantially planar optically transmissive plates disposed in an arrangement where at least some of the plates are not parallel with each other; b) inter-facet means for communicating optical signals among the plates; c) a first holographic optical element mounted with a first plate and having a first hologram that directs optical signals from the first optical transmitter node to the inter-facet means; d) a second holographic optical element mounted with a second plate and having a second hologram that directs optical signals from the inter-facet means to the first optical receiver node; e) a second transmitter mounted with the first plate and a second receiver mounted with the first plate and means for directing optical signals from the second transmitter to the second receiver. ### Claim 7 An apparatus to route the output of a first optical transmitter node to a first optical receiver node, comprising: a) a plurality of substantially planar optically transmissive plates disposed in an arrangement; b) inter-facet means for communicating optical signals among the plates: c) a first holographic optical element mounted with a first plate and having a first hologram that directs optical signals from the first optical transmitter node to the inter-facet means: d) a second holographic optical element mounted with a second plate and having a second hologram that directs optical signals from the inter-facet means to the first optical receiver node; e) a second optical transmitter node; and f) a third holographic optical element mounted with a plate and having a third hologram that directs optical signals from the second optical transmitter node to the inter-facet means. ### Claim 8 An apparatus for communicating optical signals from a first transmitter to a second receiver and from a second transmitter to a first receiver, comprising a) a holographic optical element; b) means for directing a first optical signal from the first transmitter to the holographic optical element at a first incidence angle; c) means for directing a second optical signal from the second transmitter to the holographic optical element at a second incidence angle not equal to the first incidence angle; d) means for mounting the first receiver at a first reception angle relative to the holographic optical element; and e) means for mounting the second receiver at a second reception angle not equal to the first reception angle relative to the holographic optical element; wherein the holographic optical element has a first hologram that transmits along the first reception angle optical signals arriving at the first incidence angle, and wherein the holographic optical element has a second hologram that transmits along the second reception angle optical signals arriving at the second incidence angle. ### Claim 9 An apparatus for communicating optical signals from a first transmitter to a second receiver and from a second transmitter to a first receiver, comprising a) a holographic optical element; b) means for directing a first optical signal having a first wavelength from the first transmitter to the holographic optical element; c) means for directing a second optical signal having a second wavelength different from the first wavelength from the second transmitter to the holographic optical element; d) means for mounting the first receiver at a first reception angle relative to the holographic optical element; and e) means for mounting the second receiver at a second reception angle relative to the holographic optical element not equal to the first reception angle; wherein the holographic optical element has a first hologram that transmits along the first reception angle optical signals arriving with the first wavelength, and wherein the holographic optical element has a second hologram that transmits along the second reception angle optical signals arriving with the second wavelength. ### Claim 10 An optical interconnection system comprising: a plurality of communication nodes formed on a plurality of optically transmissive planar substrates, at least some of which are not parallel with each other; means to form an optical interconnection between two of the nodes on separate substrates comprising at least one segment of the interconnection being formed by guided total internal reflection within one substrate between a first intermediate communication node and a second intermediate communication node and at least one segment of the interconnection being formed by unguided transmission between substrates between the second intermediate communication node and a third intermediate communication node on another substrate.. ### Claim 11 (depends on 10) The system of claim 10 wherein at least some of the communication nodes include holographic optical elements interposed between the substrate and sources of optical information inputs and outputs into and out of the substrate. ### Claim 12 (depends on 11) The system of claim 11 wherein the holographic optical elements comprise dichromated gelatin and the substrates comprise glass. ### Claim 13 (depends on 10) The system of claim 10 wherein the unguided transmission segment is through free space. ### Claim 14 (depends on 12) The system of claim 12 wherein the optical interconnection is a duplex communication pathway. ### Claim 15 (depends on 10) The system of claim 10 wherein at least some of the communication nodes include means to send/receive information at different output/input angle of incidence relative to the adjacent substrate plane as a function of the optical wavelength. ### Claim 16 (depends on 10) The system of claim 10 wherein the planar substrates form a polyhedron. ### Claim 17 (depends on 16) The system of claim 16 wherein the polyhedron is a solid polyhedron.