Optical waveguides – With optical coupler – Switch
Reexamination Certificate
2001-01-30
2002-11-12
Palmer, Phan T. H. (Department: 2874)
Optical waveguides
With optical coupler
Switch
C385S016000, C385S017000, C359S224200
Reexamination Certificate
active
06480645
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to structures for controlling and monitoring positions of movable switching elements in an optical switch, and more particularly to electrode structures for controlling and sensing angular positions of micro-machined micro-mirrors in an optical switching device.
2. Description of the Related Art
Increasing demands for high-speed Internet service and wireless communications are soon expected to outstrip current telecommunications capacity. Because optical fiber networks are capable of transmitting huge volumes of data at blinding speeds, telecommunications carriers are turning to optical fiber networks in an effort to meet future needs.
In order to implement tomorrow's optical fiber networks, the telecommunications industry needs new optical devices that are inexpensive, efficient, and scalable to accommodate future optical telecommunications network expansion. Telecommunications providers prefer optical fiber networks that can be reconfigured quickly and efficiently. This gives the optical network the flexibility to accommodate growth and changes in future communications patterns. The ability to reconfigure quickly and efficiently also enables the network to restore failed communications by rerouting the communications to bypass the failure.
Optical fiber networks can be reconfigured at network nodes using optical switches to change the coupling between incoming optical fibers and outgoing optical fibers. Currently under development are optical switches that use movable micro-mirrors. These optical switches couple the optical signals between input and output fibers entirely in optical form, instead of converting the optical signals to electrical signals, switching the electrical signals, and converting the switched electrical signals back to optical signals.
To successfully operate such switches, the components—including fibers, lenses, and the micro-mirrors—must be properly aligned and the angular position of the movable micro-mirrors must be precisely controlled. If the angular position of the movable micro-mirrors is off and/or if the other components are not properly aligned, some or all of the light from the input fibers will not reach the selected output fiber. At switching speeds necessary for today's optical communication needs, a micro-mirror based switch must rapidly move a mirror into position on command with minimal slew (where a slope of a micro-mirror trajectory output curve is close to a theoretically predicted one). Mirror movement must also quickly settle at a desired position to avoid signal loss. Micro-mirror switch control systems should also be insensitive to perturbations that would otherwise affect mirror position and hold maximum input-to-output optical coupling over long time scales.
Thus, there remains a need in the art for optical switch structures that can efficiently translate electrical signals into micro-mirror actuation to provide quick micro-mirror positioning. There also remains a need in the art for optical switch structures that allow reliable sensing of micro-mirror angular position to precisely control a mirror's movement and/or provide accurate position status, whether a mirror is in a static or dynamic state.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above circumstances and has as an object to provide an efficient and reliable optical switch.
The present invention has another object to provide methods for controlling an optical switch.
One aspect of the present invention is a plurality of electrodes having elongated sidewalls that are used to control movable mirror elements.
Another aspect of the present invention is a plurality of concentrically arranged segmented electrodes.
Yet another aspect of the present invention includes a structure and method for providing control to a movable mirror assembly from a freestanding conductive structure.
Still another aspect of the present invention is a plurality of segmented sidewall electrodes used for sensing a position and/or positioning a movable mirror.
Additional aspects and advantages of the invention will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the invention. The aspects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
REFERENCES:
patent: 6253001 (2001-06-01), Hoen
patent: 6396976 (2002-05-01), Little et al.
patent: 6430333 (2002-08-01), Little et al.
patent: WO 99/66354 (1999-12-01), None
Yong S. Lee et al., “A Batch-Fabricated Silicon Capacitive Pressure Transducer with Low Temperature Sensitivity,”IEEE Transactions on Electron Devices,vol. ED-29, No. 1 (Jan.) 1982, pp. 42-48.
F. Rudolf, “A Micromechanical Capacitive Accelerometer with A Two-Point Inertial-Mass Suspension,”Sensors and Actuators,vol. 4, No. 2 (Oct.) 1983, pp. 191-198.
Joseph T. Kung et al., “A Digital Readout Technique for Capacitive Sensor Applications,”IEEE Journal of Solid-State Circuits,vol. 23, No. 4, (Aug.) 1988, pp. 972-977.
Mark Van Paemel, “Interface Circuit for Capacitive Accelerometer,”Sensors and Actuators,vol. 17, Nos. 3&4 (May) 1989, pp. 629-637.
Yu-Chong Tai et al., “IC-processed Electrostatic Synchronous Micromotors,”Sensors and Actuators,vol. 20, Nos. 1&2 (Nov.) 1989, pp. 49-55.
William C. Tang, et al., “Electrostatic Comb Drive Levitation and Control Method,”IEEE Journal of Microelectromechanical Systems,vol. 1, No. 4 (Dec.) 1992, pp. 170-178.
Robert E. Mihailovich et al., “Single-Crystal Silicon Torsional Resonators,”IEEE1993, pp. 184-188.
Michael W. Putty, et al., “A Micromachined Vibrating Ring Gyroscope,”Solid-State Sensor and Actuator Workshop,Hilton Head, South Carolina, Jun. 13-16 (Jun.) 1994, pp. 213-220.
D.T. Neilson et al., “Fully Provisioned 112×112 Micro-Mechanical Optical Crossconnect with 35.8Tb/s Demonstrated Capacity,”Technical Digest Series—Post Deadline Papers, Optical Fiber Communication Conference (OSA), Mar. 7-10, 2000, pp. 1-3.
Bonadeo Nicolas H.
Chu Patrick Breckow
Lee Shi-Sheng
Park Sangtae
Peale David R.
Morgan & Lewis & Bockius, LLP
Palmer Phan T. H.
Tellium Inc.
LandOfFree
Sidewall electrodes for electrostatic actuation and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sidewall electrodes for electrostatic actuation and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sidewall electrodes for electrostatic actuation and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2948740