# US 9,521,473 B2 · Wavelength selective switch with increased frequency separation to avoid crosstalk > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,521,473 B2 - Document ID: US9521473B2 - Status: Granted - Kind: B2 - Application number: 14/618,324 - Filed: 2015-02-10 - Published: 2016-08-11 - Granted: 2016-12-13 - Earliest claimed: 2015-02-10 - Assignees: Nistica, Inc. - Applicants: Nistica, Inc. - Inventors: Jefferson L. Wagener - Web page: https://patentgrep.com/patent/US9521473B2 ## CPC - H04Q 11/0005: {Switch and router aspects} - H04Q 2011/0007: {Construction} - H04Q 2011/0016: {using wavelength multiplexing or demultiplexing} - H04Q 2011/0024: {using space switching} - H04Q 2011/0026: {using free space propagation (e.g. lenses, mirrors)} - H04Q 2011/003: {using switches based on microelectro-mechanical systems [MEMS]} - H04Q 2011/0035: {using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical} - H04Q 2011/0049: {Crosstalk reduction; Noise; Power budget} - H04Q: SELECTING (switches, relays, selectors H01H; wireless communication networks H04W) ## Abstract An optical device incorporates into the same physical structure the functionality of two or more wavelength selective switches. The wavelength components associated with the first optical switch are isolated from the wavelength components associated with the second optical switch by their spatial displacement along one axis on a programmable optical phase modulator. Remaining crosstalk between the components is reduced by spatially separating the components of the two wavelength switches having the same wavelength along another axis of the programmable optical phase modulator. ## Claims ### Claim 1 An optical device, comprising: an optical port array having a first plurality of ports for receiving optical beams and a second plurality of ports for receiving optical beams, an offset axis extending through both the first and second planes, the ports in the first plurality of ports being laterally displaced from the ports in the second plurality of ports along the offset axis; a dispersion element receiving a first of the optical beams from one of the first plurality of ports and a second of the optical beams from the second plurality of ports and spatially separating the optical beams into respective first and second pluralities of wavelength components along first and second wavelength dispersion axes that are each orthogonal to a port axis, the first plurality of ports being interleaved with the second plurality of ports along the port axis, the first plurality of ports having optical axes extending along a first direction and the second plurality of ports having optical axes extending along a second direction, the first and second directions being different from one another, at least one of the first and second directions being non-orthogonal to the port axis; a focusing element for focusing the first and second pluralities of wavelength components; and a programmable optical phase modulator for receiving the focused plurality of wavelength components, the modulator being configured to steer the wavelength components received from any one of the first plurality of ports to a selected one of the first plurality of ports and being further configured to steer the wavelength components received from any one of the second plurality of ports to a selected one of the second plurality of ports. ### Claim 2 (depends on 1) The optical device of claim 1 wherein both the first and second directions are non-orthogonal to the offset axis and defines an acute angle greater than 0° with respect to one another. ### Claim 3 (depends on 1) The optical device of claim 1 wherein the dispersive element is selected from the group consisting of a diffraction grating and a prism. ### Claim 4 (depends on 1) The optical device of claim 1 wherein the first and second wavelength dispersion axes and the programmable optical phase modulator extend in a common plane. ### Claim 5 (depends on 1) The optical device of claim 1 wherein the first plurality of ports extend in a first plane and the second plurality of ports extend in a second plane parallel to the first plane. ### Claim 6 (depends on 5) The optical device of claim 5 wherein the offset axis extends orthogonally through both the first and second plane. ### Claim 7 (depends on 1) The optical device of claim 1 wherein the programmable optical phase modulator includes a liquid crystal-based phase modulator. ### Claim 8 (depends on 7) The optical device of claim 7 wherein the liquid crystal-based phase modulator is a LCoS device. ### Claim 9 (depends on 1) The optical device of claim 1 further comprising an optical system for magnifying the optical beam received from the optical port array and directing the magnified optical beam to the dispersion element. ### Claim 10 (depends on 9) The optical device of claim 9 wherein the optical system has a first magnification factor in a first direction and a second magnification factor in a second direction orthogonal to the first direction, the first magnification factor being different from the second magnification factor. ### Claim 11 (depends on 10) The optical device of claim 10 wherein the first direction is parallel to at least one of the wavelength dispersion axes along which the optical beam is spatially separated, the first magnification factor being less than the second magnification factor. ### Claim 12 A method for directing wavelength components of an optical beam from an input port of a port array to at least one output port of the port array, comprising: receiving a first optical beam at a first input port of the port array associated with a first wavelength selective switch; receiving a second optical beam at a second input port of the port array associated with a second wavelength selective switch; magnifying the optical beam in a first direction and a second direction orthogonal to the first direction; after magnifying the optical beam, spatially separating the wavelength components of the first and second optical beams; focusing the spatially separated wavelength components onto a programmable optical phase modulator so that the wavelength components of the first and second optical beams are spatially separated along at least a pixel axis on the modulator, the wavelength components of the first optical beam being spatially offset from the wavelength components of the second optical beam along the pixel axis; and adjusting a phase shift profile of the programmable optical phase modulator to selectively direct individual ones of the wavelength components received from the first input port to another port of the port array associated with the first wavelength selective switch and being further configured to selectively direct individual ones of the wavelength components received from the second input port to another port of the port array associated with the second wavelength selective switch. ### Claim 13 (depends on 12) The method of claim 12 wherein the programmable optical phase modulator includes a liquid crystal-based phase modulator. ### Claim 14 (depends on 13) The method of claim 13 wherein the liquid crystal-based phase modulator is a LCoS device. ### Claim 15 (depends on 12) The method of claim 12 wherein the first direction is parallel to the wavelength dispersion axis along which the first and second optical beams are spatially separated, the magnification in the first direction being less than the magnification in the second direction. ### Claim 16 An optical device, comprising: an optical port array having a first plurality of ports for receiving optical beams and a second plurality of ports for receiving optical beams, the first plurality of ports extending in a first plane and the second plurality of ports extending in a second plane parallel to the first plane, an offset axis extending through both the first and second planes, the ports in the first plurality of ports being laterally displaced from the ports in the second plurality of ports along the offset axis; a dispersion element receiving a first of the optical beams from one of the first plurality of ports and a second of the optical beams from the second plurality of ports and spatially separating the optical beams into respective first and second pluralities of wavelength components along first and second wavelength dispersion axes that are each orthogonal to a port axis, the first plurality of ports having optical axes extending along a first direction and the second plurality of ports having optical axes extending along a second direction, the first and second directions being different from one another, at least one of the first and second directions being non-orthogonal to the port axis; a focusing element for focusing the first and second pluralities of wavelength components; and a programmable optical phase modulator for receiving the focused plurality of wavelength components, the modulator being configured to steer the wavelength components received from any one of the first plurality of ports to a selected one of the first plurality of ports and being further configured to steer the wavelength components received from any one of the second plurality of ports to a selected one of the second plurality of ports. ### Claim 17 (depends on 16) The optical device of claim 16 wherein both the first and second directions are non-orthogonal to the offset axis and defines an acute angle greater than 0° with respect to one another. ### Claim 18 (depends on 16) The optical device of claim 16 wherein the first and second wavelength dispersion axes and the programmable optical phase modulator extend in a common plane. ### Claim 19 (depends on 16) The optical device of claim 16 wherein the first plurality of ports extend in a first plane and the second plurality of ports extend in a second plane parallel to the first plane. ### Claim 20 (depends on 19) The optical device of claim 19 wherein the offset axis extends orthogonally through both the first and second plane. ### Claim 21 (depends on 16) The optical device of claim 16 wherein the programmable optical phase modulator includes a liquid crystal-based phase modulator. ### Claim 22 (depends on 21) The optical device of claim 21 wherein the liquid crystal-based phase modulator is a LCoS device. ### Claim 23 (depends on 16) The optical device of claim 16 wherein the dispersive element is selected from the group consisting of a diffraction grating and a prism. ### Claim 24 (depends on 16) The optical device of claim 16 further comprising an optical system for magnifying the optical beam received from the optical port array and directing the magnified optical beam to the dispersion element. ### Claim 25 (depends on 24) The optical device of claim 24 wherein the optical system has a first magnification factor in a first direction and a second magnification factor in a second direction orthogonal to the first direction, the first magnification factor being different from the second magnification factor. ### Claim 26 (depends on 25) The optical device of claim 25 wherein the first direction is parallel to at least one of the wavelength dispersion axes along which the optical beam is spatially separated, the first magnification factor being less than the second magnification factor. ### Claim 27 An optical device, comprising: an optical port array having a first plurality of ports for receiving optical beams and a second plurality of ports for receiving optical beams, an offset axis extending through both the first and second planes, the ports in the first plurality of ports being laterally displaced from the ports in the second plurality of ports along the offset axis; a dispersion element receiving a first of the optical beams from one of the first plurality of ports and a second of the optical beams from the second plurality of ports and spatially separating the optical beams into respective first and second pluralities of wavelength components along first and second wavelength dispersion axes that are each orthogonal to a port axis, the first plurality of ports having optical axes extending along a first direction and the second plurality of ports having optical axes extending along a second direction, the first and second directions being different from one another, at least one of the first and second directions being non-orthogonal to the port axis; a focusing element for focusing the first and second pluralities of wavelength components; and a programmable optical phase modulator for receiving the focused plurality of wavelength components, the modulator being configured to steer the wavelength components received from any one of the first plurality of ports to a selected one of the first plurality of ports and being further configured to steer the wavelength components received from any one of the second plurality of ports to a selected one of the second plurality of ports and; wherein the optical system has a first magnification factor in a first direction and a second magnification factor in a second direction orthogonal to the first direction, the first magnification factor being different from the second magnification factor. ### Claim 28 (depends on 27) The optical device of claim 27 wherein both the first and second directions are non-orthogonal to the offset axis and defines an acute angle greater than 0° with respect to one another. ### Claim 29 (depends on 27) The optical device of claim 27 wherein the first plurality of ports are interleaved with the second plurality of ports along the port axis. ### Claim 30 (depends on 27) The optical device of claim 27 wherein the first and second wavelength dispersion axes and the programmable optical phase modulator extend in a common plane. ### Claim 31 (depends on 27) The optical device of claim 27 wherein the offset axis extends orthogonally through both the first and second plane. ### Claim 32 (depends on 27) The optical device of claim 27 wherein the programmable optical phase modulator includes a liquid crystal-based phase modulator. ### Claim 33 (depends on 32) The optical device of claim 32 wherein the liquid crystal-based phase modulator is a LCoS device. ### Claim 34 (depends on 27) The optical device of claim 27 wherein the dispersive element is selected from the group consisting of a diffraction grating and a prism. ### Claim 35 (depends on 27) The optical device of claim 27 further comprising an optical system for magnifying the optical beam received from the optical port array and directing the magnified optical beam to the dispersion element. ### Claim 36 (depends on 27) The optical device of claim 27 wherein the first direction is parallel to at least one of the wavelength dispersion axes along which the optical beam is spatially separated, the first magnification factor being less than the second magnification factor.