Onix Microsystems, Inc.

Analog Devices,inc.

University of California

Other

Orix Microsystems, Inc.

Behrang Behin

Michael J Daneman

Satinderpall S Pannu

Meng-Hsiung Kiang

Kam Y Lau

Richard S Muller

Boris Kobrin

Timothy E Beerling

Chuang-Chia Lin

Kam-Yin Lau

Murali Chaparala

Gary M Zalewski

David Horsley

Scott D Dalton

Franklin Joseph Wall

Robert A Conant

David Lerner

Mark W Chang

Stephen Panyko

Methods for directing an optical beam and for making an apparatus for directing an optical beam are described. One such method may include applying a first force to a plate to move the plate from a first angular orientation to a second angular orientation wherein the plate contacts a stop in the second angular orientation. A reflective portion of the plate is stopped from rotating beyond the second angular orientation. A second force can be applied between the plate and the stop to hold the plate against the stop in a plane substantially parallel to a substantially planar surface of the stop. An apparatus for directing an optical beam may be made by coupling an array of plates to a base assembly wherein each plate is movable between a first angular orientation and a second angular orientation.

Method for directing an optical beam and a method for manufacturing an apparatus for directing an optical beam

An optical cross-connect switch comprises a base (), a flap () and one or more electrically conductive landing pads () connected to the flap (). The flap () has a bottom portion that is movably coupled to the base () such that the flap () is movable with respect to a plane of the base () from a first orientation to a second orientation. The one or more landing pads () are electrically isolated from the flap () and electrically coupled to be equipotential with a landing surface.

Optical cross-connect system

A beam steering module comprised of a mirror stack array in close proximity to a collimator array controllably steers photons along two axis and in a direction substantially less than 90 degrees to the collimator orientation. Several configurations of the module are described using single and double axis mirror rotation and relay optics. Optical telecommunications switches are shown using modules coupled to each other along flat and curved surfaces, with and without use of fold mirror and enabling a plurality of configuration options including photodetector optical power monitoring schemes that require no external power taps.

Three dimensional optical switches and beam steering modules

Microstructure apparatus and methods are described. An exemplary movable microstructure apparatus includes a base, a plate, and a stop. The plate may be coupled to the base through a flexure, so that the plate is movable between a first angular orientation and a second angular orientation. The stop may be configured to contact the bottom portion of the plate in a contact area when the plate is in the second angular orientation. Alternatively, the stop may be configured to contact the plate in a contact area sized so that upon application of an electrostatic bias between the plate and the stop, a sufficient force holds the plate against the stop. Alternatively, the stop may have a substantially planar surface configured to contact the plate in a contact area sized so that, upon application of a force to the plate substantially normal to the substantially planar surface of the stop, a sufficient force holds the plate against the stop such that the plate lies in a plane substantially parallel to the substantially planar surface of the stop.

Global mechanical stop

Methods for directing an optical beam and for making an apparatus for directing an optical beam are described. One such method may include applying a first force to a plate to move the plate from a first angular orientation to a second angular orientation wherein the plate contacts a stop in the second angular orientation. A second force can be applied between the plate and the stop to hold the plate against the stop in a plane substantially parallel to a substantially planar surface of the stop. An apparatus for directing an optical beam may be made by coupling an array of plates to a base assembly wherein each plate is movable between a first angular orientation and a second angular orientation. An array of apertures may be formed in a stop assembly wherein the stop assembly is coupled to the base assembly and each aperture is positioned to contact its respective plate when the plate is in a second angular orientation.

MEMS structures may be formed on a substrate by forming a series trenches filled with etch-stop material in the device layer, followed by an isotropic etch of the device material stopping on the etch-stop material. This approach provides a controlled release method where the exact timing of the isotropic release etch becomes non-critical. Further, using this method, structures with significant topology may be fabricated while keeping the wafer topology to a minimum during processing until the very end of the process. Using the method of this invention, features with large topology may be formed while keeping the wafer topology to a minimum until the very end of the process.

Fabrication and controlled release of structures using etch-stop trenches

A microelectromechanical (MEMS) apparatus has a base and a flap with a portion coupled to the base so that the flap may move out of the plane of the base between first and second position. The base may have a cavity with largely vertical sidewalls that contact a portion of the flap when the flap is in the second position Electrodes may be placed on the vertical sidewalls and electrically isolated from the base to provide electrostatic clamping of the flap to the sidewall. The base may be made from a substrate portion of a silicon-on-insulator (SOI) wafer and the flap defined from a device layer of the SOI wafer. The flap may be connected to the base by one or more flexures such as torsional beams. An array of one or more of such structures may be used to form an optical switch.

MEMS mirrors with precision clamping mechanism

A two-dimensional scanner consists of a rotatable gimbal structure with vertical electrostatic comb-drive actuators and sensors. The scanner's two axes of rotation may be controlled independently by activating two sets of vertical comb-drive actuators. The first set of vertical comb-drive actuator is positioned in between a outer frame of the gimbal structure and the base, and the second set of vertical comb-drive actuator is positioned in between the inner part of the gimbal structure and the outer frame of the gimbal structure. The inner part of the gimbal structure may include a reflective surface, and the device may be used as a mirror. Furthermore, the capacitance of the vertical comb-drives may be measured to monitor the angular position of the mirror, and the capacitive position-monitoring signal may be used to implement closed-loop feedback control of the mirror angle. The two-dimensional scanner may be fabricated in a semiconductor process. Two-dimensional scanners may be used to produce fiber-optic switches.

Two-dimensional gimbaled scanning actuator with vertical electrostatic comb-drive for actuation and/or sensing

Disclosed is an apparatus and method for detecting whether rotatable MEMS elements are in the &ldquo;on&rdquo; or &ldquo;off&rdquo; position. Embodiments of the invention have application in devices switches that employ mirrors that move between an &ldquo;on&rdquo; or &ldquo;off&rdquo; position, wherein they reflect light from an input fiber into an output fiber in the &ldquo;on&rdquo; position, and allow the light to pass in the &ldquo;off&rdquo; position. Electrodes are positioned in the device such that the mirrors are close to, and therefor capacitively coupled to, a different electrode depending on whether they are in the &ldquo;on&rdquo; or &ldquo;off&rdquo; position. This invention is especially useful for switches that already employ electrodes for electrostatic clamping of mirrors in one or more positions, since those same electrodes can be used both to electrostatically clamp the mirrors and to sense their position. The method described in this invention comprises sensing of the capacitance between the mirrors and the one or more electrodes used to clamp the mirrors in its one or more position in order to detect which of the positions the mirrors are clamped in. Furthermore, the magnitude of the capacitances can be monitored to detect improper clamping.

Capacitive sensing scheme for digital control state detection in optical switches

A device having a landing pad structure on an underside of a device and method for fabricating same. The device is formed from a device layer with at least one landing pad protruding from an underside thereof. The landing pad is attached to the device layer by a plug passing through an opening in the device layer. The device may be attached to the device layer by one or more compliant flexures, which allow the device to rotate in and out of a plane defined by the device layer. The landing pads are fabricated by forming one or more vias through the device layer. An underlying sacrificial layer is then partially etched to form one or more depressions at locations corresponding to locations of the vias in the device layer. The vias and depressions are then filled with a landing pad material to form a structure having one or more landing pads protruding from an underside of the device layer. The sacrificial layer is subsequently removed to release the device. Particular embodiments of both methods may be applied to fabricating microelectromechanical systems (MEMS) especially MEMS mirrors. The various embodiments are well suited to use with silicon on insulator (SOI) substrates.

Mechanical landing pad formed on the underside of a MEMS device

A multi-layer vertical comb-drive actuator includes a first comb structure having a plurality of first comb fingers and a second comb structure having a plurality of second comb fingers, wherein the first and second comb fingers are substantially interdigitated. The first and second comb fingers may include two or more stacked conductive layers electrically isolated from each other by an insulating layer or an air gap. Alternatively, either the first or second comb fingers may include only one conductive layer. An application of a voltage between the first and second comb fingers causes the second comb structure to move relative to the first comb structure. The present invention includes a 2D-gimble configuration to rotate a movable element along two axis.

Multi-layer, self-aligned vertical combdrive electrostatic actuators and fabrication methods

A method for rotating a combdriven device about an axis uses applied bias force along with applied voltage between first and second comb fingers to controllably rotate the device about one or two axis. One mode of the present invention includes measuring the position of a rotating element and providing feedback to control the angular position thereof by changing bias force and/or drive voltage. The present invention can be employed with prior-art staggered combdrives, single layer self-aligned combdriven devices, and in a broad range of applications in optical telecommunication switching, video, biomedical, inertial sensors, and in storage magnetic disk drives.

Biased rotatable combdrive actuator methods

A method of fabricating multi-layer vertical comb-drive actuator that includes a first comb structure having a plurality of first comb fingers and a second comb structure having a plurality of second comb fingers, wherein the first and second comb fingers are substantially interdigitated. The present invention includes masking and etching of a structure that contains these multiple layers, wherein the first and second comb fingers are simultaneously fabricated. The first and second comb fingers may include two or more stacked conductive layers electrically isolated from each other by an insulating layer or an air gap. Alternatively, either the first or second comb fingers may include only one conductive layer.

Rotating devices including actuators and position sensors that employ combdrives are described. One design of a combdrive fabricated from a single layer is provided such that, in a nominal state, the two sets of comb fingers are substantially interdigitated according to a predetermined engagement. A rotating element may be attached to a rotatable flexure disposed along an axis and coupled to the comb fingers along with a biasing element attached to the rotating element to cause the comb fingers along with the rotating element to undergo a controlled angular displacement from the initial engagement and in response to feedback from sensing the position of the movable or rotating element. A voltage may be applied between comb fingers to cause the rotating element to undergo further rotation about the axis in a predetermined manner. Alternatively, a time-vary biasing force may be exerted on the rotating element, causing the first comb fingers along with the rotating element to undergo further rotation about the axis in a predetermined manner. The combdriven device can serve as both rotating actuators and position sensor. By arranging two such combdrives in a gimbaled structure bi-axial rotating actuators and position sensors may be constructed. The combdrive devices of the present invention can be employed in a broad range of applications, including biomedical devices, optical devices for tracking and display, telecommunication devices such as fiber-optic switches, inertial sensors, and magnetic disk drives.

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Berkeley, CA, United States of America

Behrang Behin