# US 7,613,370 B2 · Optical switch and method of adjusting optical switch > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,613,370 B2 - Document ID: US7613370B2 - Status: Granted - Kind: B2 - Application number: 12/074,060 - Filed: 2008-02-29 - Published: 2008-10-02 - Granted: 2009-11-03 - Earliest claimed: 2007-03-28 - Assignees: Fujitsu Limited - Inventors: Kohei Shibata; Hirofumi Aota; Tamotsu Akashi; Toshiya Kishida; Hiroyuki Furukawa - Web page: https://patentgrep.com/patent/US7613370B2 ## CPC - G02B 6/352: {the reflective optical element having a shaped reflective surface, e.g. a reflective element comprising several reflective surfaces or facets that function together} - G02B 6/3556: {NxM switch, i.e. regular arrays of switches elements of matrix type constellation} - G02B 6/356: {in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links (switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An optical switch includes an input port into which a multiplexed optical signal is input; a dispersing unit that, according to wavelength, disperses the multiplexed optical signal into a plurality of optical signals that are each dispersed in a unique direction; a converging unit that converges the dispersed optical signals; plural mirrors that are arrayed forming a single row in a plane and reflecting the converged optical signals, respectively; and plural output ports through which the reflected optical signals are output. Each of the mirrors has a concave reflective surface that is in the plane and of a predetermined curvature about an axis parallel to the plane. ## Claims ### Claim 1 An optical switch comprising: an input port from which a multiplexed optical signal is input; a dispersing unit that disperses the multiplexed optical signal into a plurality of optical signals; a converging unit that converges the dispersed optical signals; a plurality of mirrors that reflect the converged optical signals, respectively; and a plurality of output ports through which the reflected optical signals are output, respectively, wherein each of the mirrors rotates about a first axis and a second axis to change a first reflection angle and a second reflection angle thereof, respectively, and has a concave reflective surface having a predetermined curvature about the second axis about which each of the mirrors rotates for switching between the output ports, and the optical switch further comprises a control unit that controls the first reflection angle of each of the mirrors such that transmissivities of wavelengths included in each of the optical signals output from the output ports become substantially the same, and controls the second reflection angle of each of the mirrors such that a transmissivity of each of the optical signals output from the output ports becomes a desired level. ### Claim 2 (depends on 1) The optical switch according to claim 1, wherein the first reflection angle varies according to a point on the converging unit through which the dispersed optical signals pass respectively. ### Claim 3 (depends on 1) The optical switch according to claim 1, wherein the predetermined curvature differs according to a point on the converging unit through which the dispersed optical signals pass respectively. ### Claim 4 (depends on 1) The optical switch according to claim 1, wherein the second reflection angle differs according to the predetermined curvature. ### Claim 5 (depends on 1) The optical switch according to claim 1, wherein the second reflection angle varies according to the first reflection angle. ### Claim 6 (depends on 1) The optical switch according to claim 1, wherein each of the mirrors has a curvature about the second axis that is larger than the predetermined curvature. ### Claim 7 (depends on 6) The optical switch according to claim 6, wherein each of the mirrors includes a rib along the first axis. ### Claim 8 (depends on 1) The optical switch according to claim 1, further comprising a monitoring unit that monitors the transmissivities, wherein the control unit controls the first reflection angle based on the transmissivities. ### Claim 9 (depends on 1) The optical switch according to claim 1, wherein the converging unit is a transmissive convex lens. ### Claim 10 (depends on 1) The optical switch according to claim 1, wherein the converging unit is a reflective concave mirror. ### Claim 11 A method of adjusting an optical switch that includes a dispersing unit that disperses an input multiplexed optical signal into a plurality of optical signals and a plurality of mirrors that reflect the optical signals to a plurality of output ports, respectively, wherein each of the mirrors rotates about a first axis and a second axis to change a first reflection angle and a second reflection angle thereof, respectively, and has a concave reflective surface having a predetermined curvature about the second axis about which each of the mirrors rotates for switching between the output ports, the method comprising: first-adjusting the predetermined curvature and the first reflection angle of each of the mirrors such that transmissivities of wavelengths included in each of the optical signals output from the output ports become substantially the same; and second-adjusting the second reflection angle of each of the mirrors such that a transmissivity of each of the optical signals output from the output ports becomes a desired level.