Optical waveguides – With optical coupler – Switch
Reexamination Certificate
2001-10-05
2004-07-13
Sanghavi, Hemang (Department: 2874)
Optical waveguides
With optical coupler
Switch
C385S016000, C385S019000, C310S309000, C359S198100, C359S199200, C359S223100, C359S224200, C359S226200
Reexamination Certificate
active
06763161
ABSTRACT:
SCOPE OF THE INVENTION
The present invention relates generally to optical microswitches and more particularly to optical microswitches utilizing electrostatic microactuators with comb drive assemblies.
BACKGROUND
Optical switches have heretofore been provided. Many of such switches use macroscopic rotators. Switches utilizing electromagnetic motors have been disclosed to move either an input optical fiber or a refractive or reflective element interspersed between input and output optical fibers. Examples of such designs that use piezoelectric elements to move refractive or reflective elements are shown in U.S. Pat. No. 5,647,033 to Laughlin, U.S. Pat. No. 5,748,813 to Buchin and U.S. Pat. No. 5,742,712 to Pan et al. All of switches are relatively large and expensive.
A micromachined optical switch is disclosed in U.S. Pat. No. 5,446,811 to Field et al. and uses a bimetallic element to displace an optical fiber into alignment with one or more optical fibers. Such switch, however, is not easily extendable to a switch having a relatively large number of output fibers and bimetallic actuators are relatively slow.
Micromachined devices to tilt or rotate mirrors are known in the prior art, but suffer from various limitations. A one dimensional or two dimensional mirror rotator that tilts about axes in the plane of the substrate used to fabricate the device is disclosed in Dhuler et al., “A Novel Two Axis Actuator for High Speed Large Angular Rotation”, Transducers '97, Vol. 1, pp. 327-330. The actuator uses a variable gap parallel plate capacitor as the drive element, which suffers from non-linear response of force or angular displacement as a function of applied voltage. A similar type of tilting mirror is described in Kruth et al., “Silicon Mirrors and Micromirror Arrays for Spatial Laser Beam Modulation”, Sensors and Actuators A 66 (1998), pp. 76-82. Such mirrors are typically designed for use in projection displays or in scanners for bar code reading. A scanner using surface micromachining technology and having a mirror that is tilted out of the plane of the fabrication is described in Kiang et al., “Surface-Micromachined Electrostatic-Comb Driven Scanning Micromirrors for Barcode Scanners”, Ninth Annual Int. Workshop on Micro Electro Mechanical Systems, San Diego, 1996, pp. 192-19997. All of such devices tend to have difficulty in maintaining flatness and smoothness in the mirror elements and may have difficulty in precise static positioning of the mirror due to hysteresis in the coupling between the electrostatic comb drive actuator in the plane of the substrate and the mirror element out of the substrate plane.
In general, it is an object of the present invention to provide a relatively inexpensive optical microswitch having a small form factor.
Another object of the invention is to provide an optical microswitch of the above character in which the reflective face of a micromirror rotates in the focal plane of a focusing lens.
Another object of the invention is to provide an optical microswitch of the above character in which first and second micromirrors are closely packed and disposed in the focal plane of a focusing lens.
Another object of the invention is to provide an optical microswitch of the above character which is capable of coupling visible or infrared light into an optical fiber with low transmission losses.
Another object of the invention is to provide an optical microswitch of the above character which has relatively fast switching times.
Another object of the invention is to provide an optical microswitch of the above character in which the mirror is capable of angular rotations over a relatively large range.
SUMMARY OF THE INVENTION
The present invention provides an optical microswitch comprising a support body and first and second output fibers. A rotary electrostatic microactuator is carried by the body and extends in a plane. A micromirror is disposed out of the plane. The microactuator has a mirror holder coupled to the micromirror and at least one comb drive assembly coupled to the mirror holder for driving the micromirror about an axis of rotation extending perpendicular to the plane between a first position for reflecting a laser beam to the first output fiber and a second position for reflecting the laser beam to the second output fiber.
REFERENCES:
patent: 5000534 (1991-03-01), Watanabe et al.
patent: 5025346 (1991-06-01), Tang et al.
patent: 5153870 (1992-10-01), Lee et al.
patent: 5446811 (1995-08-01), Field et al.
patent: 5621829 (1997-04-01), Ford
patent: 5647033 (1997-07-01), Laughlin
patent: 5742712 (1998-04-01), Pan et al.
patent: 5748812 (1998-05-01), Buchin
patent: 5850375 (1998-12-01), Wilde et al.
patent: 5982585 (1999-11-01), Fan et al.
patent: 6000280 (1999-12-01), Miller et al.
patent: 6215921 (2001-04-01), Lin
patent: 6301403 (2001-10-01), Heanue et al.
patent: 6360035 (2002-03-01), Hurst et al.
patent: 6526194 (2003-02-01), Laor
patent: 0650133 (1995-04-01), None
V. Dhuler, et al.; “A Novel Two Axis Actuator for High Speed Large Angular Rotation”, 1997 International Conference on Solid-State Sensors and Actuators Chicago, Jun. 16-19, 1997, (1997) IEEE, pp. 327-330.
L. Field, et al.; “Micromachined 1×2 Optical Fiber Switch”, Hewlett-Packard Laboratories, (1996) Elsevier Science (Sensors and Actuators A-53), pp. 311-315.
Meng-Hsiung Kiang, et al.; “Surface-Micromachined Electrostatic-Comb Driven Scanning Micromirrors for Barcode Scanners”, Department of Electrical Engineers and Computer Sciences, University of California at Berkeley, (1996) IEEE, pp. 192-197.
S. Kurth, et al.; “Silicon Mirrors and Micromirror Arrays for Spatial Laser Beam Modulation”, Technical University Chemnitz-Zwickau. Department of Electrical Engineering & Information Technology, Germany, (1997) Elsevier Science (Sensors and Actuators A-66). pp. 76-82.
Heanue John F.
Jerman John H.
Dorsey & Whitney LLP
IOLON, Inc.
Sanghavi Hemang
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