Xerox Corporation

Massachusetts Institute of Technology

Elmer S Hung

Andrew A Berlin

Stephen D Senturia

Erik R Deutsch

Feng Zhao

A method of redirecting light using an actuatable two-layer diffraction grating structure, the method having applications in wavelength-division multiplexed systems. An optical add/drop modulator (OADM) including an actuatable diffraction grating, for use with a wavelength-division multiplexed signal. An OADM having an optical source located off the main pathway to direct a optical carrier to be added onto the actuatable diffraction grating such that the carrier is diffracted into the main pathway. A detector to measure signal strength for use with an optical processor, the optical processor having an actuatable structure having gaps between the actuated portion of the structure. The detector detecting the portions of light diffracted by the gaps.

Methods and apparatus for diffractive optical processing using an actuatable structure

The invention provides an electrostatically-controllable diffraction grating including a plurality of electrically isolated and stationary electrodes disposed on a substrate. At least one row of a plurality of interconnected actuation elements is provided, with each actuation element suspended, by a corresponding mechanically constrained support region, over the substrate by a vertical actuation gap and including a conducting actuation region connected to the corresponding support region and disposed in a selected correspondence with at least one substrate electrode. A mirror element is provided, for at least one actuation element in at least one row of actuation elements, including an optically reflecting upper surface, and being vertically suspended over a corresponding actuation element by a mechanically constrained mirror support region that is connected to the corresponding actuation element and that defines a vertical mirror gap. A mirror deflection region connected to the mirror support region and is free to be deflected through the mirror gap. The mirror gap is less than the actuation gap of a corresponding actuation element and is selected to produce controlled and stable displacement of the actuation region of a corresponding actuation element through a displacement range to a specified point in the actuation gap when an actuation voltage is applied between an actuation region and a corresponding stationary electrode. This enables diffraction of a beam of light incident on the grating as the light beam is reflected from the upper surfaces of the mirror elements.

Electrostatically-controllable diffraction grating

A microsensor including a VCSEL for use in a MEMS. By coupling the top mirror of the VCSEL to the micromechanical structure, either directly or indirectly, the motion of the micromechanical structure in response to a physical phenomenon can directly modulate the wavelength of the light emitted from the VCSEL. Also, a method for sensing and transmitting information about the configuration or motion of a mechanical structure. The method includes coupling the top mirror of a VCSEL to the mechanical structure that directly encodes information about the motion into the frequency of light emitted by the VCSEL.

Microsensor including a VCSEL and method for electro-mechanical coupling of microsensors

A MEMS-based system that enables low cost, low power, single chip realization of real-time signal detection and fault diagnosis. The system is suitable for analyzing the time-varying properties of a signal that are important for condition-based monitoring of electro-mechanical machines or structures. The system includes mechanical sensors that sense input signals such as vibration, signal templates of fault conditions, logic units that detect, store, and compare signal features to provide a diagnostic state, and an output readout mechanism to couple the diagnostic state to readout device that provides an external signal.

Microelectromechanical mechanisms for real-time mechanical vibration signature monitoring and analysis

A micromechanical resonator including a motion arresting mechanism to rapidly damp the vibration of a resonator beginning at any given moment in time to remove vibration caused by previous events. An electrostatic clamp uses a bias voltage between an electrode and the resonator to damp the resonator and return it to its equilibrium position. A mechanical clamp includes an actuator that forces the mechanical clamp to contact the resonator. These micromechanical resonators facilitate condition based monitoring of complex electromechanical machines and components by allowing signature analysis in multiple temporal and frequency domains.

Micromechanical discrete time and frequency characterization of signals via resonator clamping and motion-arresting mechanisms

A bistable sensor with a tunable threshold for use in microelectromechanical systems. The sensor uses electrostatic force to modify the threshold and to disable the sensor in a deflected position once a sustained extreme in vibration is detected. Potential applications include mechanical implementations of signature analysis to automatically eliminate large amplitude noise at a specific frequency, shock detection without requiring quiescent DC power consumption, and determination of the magnitude of a shock.

Bistable mechanical sensors capable of threshold detection and automatic elimination of excessively high amplitude data

There is provided an electrostatically-controllable actuator having a stationary electrode, with an actuating element separated from the stationary electrode by an actuation gap. The actuating element includes a mechanically constrained support region, a deflection region free to be deflected through the actuation gap, and a conducting actuation region extending from about the support region to the deflection region. A commonality in area between the actuation region and the stationary electrode is selected to produce controlled and stable displacement of the deflection region over a displacement range, e.g., extending to a specified point in the actuation gap, when an actuation voltage is applied between the actuation region and the stationary electrode. This range of stable displacement, which can be stable bending, can extend to a point greater than about &frac13; of the actuation gap, or even through the full actuation gap. As a result, the invention overcomes the limitation of &frac13; gap actuation of conventional electrostatic actuation configurations.

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Foster City, CA, United States of America

Elmer S Hung