University of California

Leland Stanford Junior University

Other

Analog Devices,inc.

Lgc Wireless, Inc.

Kam-Yin Lau

Constance J Chang-Hasnain

Richard S Muller

Behrang Behin

Meng-Hsiung Kiang

Michael J Daneman

Robert A Conant

Jocelyn T Nee

Anujan Varma

Timothy E Beerling

Connie J Chang-Hasnain

Joseph W Goodman

Satinderpall S Pannu

Adam L Schwartz

Lars E Eng

Rashit F Nabiev

Sui F Lim

Janice A Hudgings

A staggered torsional electrostatic combdrive includes a stationary combteeth assembly and a moving combteeth assembly with a mirror and a torsional hinge. The moving combteeth assembly is positioned entirely above the stationary combteeth assembly by a predetermined vertical displacement during a combdrive state. A method of fabricating the staggered torsional electrostatic combdrive includes the step of deep trench etching a stationary combteeth assembly in a first wafer. A second wafer is bonded to the first wafer to form a sandwich including the first wafer, an oxide layer, and the second wafer. A moving combteeth assembly is formed in the second wafer. The moving combteeth assembly includes a mirror and a torsional hinge. The moving combteeth assembly is separated from the first wafer by the oxide layer. The oxide layer is subsequently removed to release the staggered torsional electrostatic combdrive.

Staggered torsional electrostatic combdrive and method of forming same

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 staggered torsional electrostatic combdrive includes a stationary combteeth assembly and a moving combteeth assembly with a mirror and a torsional hinge. The moving combteeth assembly is positioned entirely above the stationary combteeth assembly by a predetermined vertical displacement during a combdrive resting state. A method of fabricating the staggered torsional electrostatic combdrive includes the step of deep trench etching a stationary combteeth assembly in a first wafer. A second wafer is bonded to the first wafer to form a sandwich including the first wafer, an oxide layer, and the second wafer. A moving combteeth assembly is formed in the second wafer. The moving combteeth assembly includes a mirror and a torsional hinge. The moving combteeth assembly is separated from the first wafer by the oxide layer. The oxide layer is subsequently removed to release the staggered torsional electrostatic combdrive.

This invention provides a cellular network architecture in which traffic channel resources are centralized and dynamically allocated to remote cells according to the demand. The present invention provides a method for maximizing capacity resources by dynamically sectorizing cells in a CDMA (Code Division Multiple Access) cellular network. The present invention further provides a CDMA cellular communications network in which centralized traffic channel resources are distributed to remote cells by use of WDM (Wavelength Division Multiplexing) on optical fibers and remote cells are dynamically sectorized according to the traffic demand and the grade-of-service requirement. The primary advantage of the present invention is that it enables a cellular network to dynamically manage and optimally utilize its capacity resources without having to change its hardware design, in contrast to the static and passive nature of the prior art cellular networks. The present invention provides a cost-effective build-out strategy for cellular network operators.

Dynamic sectorization in a CDMA cellular system employing centralized base-station architecture

A laser comprises a first contact to receive an active region control signal, a second contact to receive an optical absorber control signal, and a sandwich of distributed Bragg reflector mirror stacks. Each distributed Bragg reflector mirror stack has an alternate doping with respect to an adjacent distributed Bragg reflector mirror stack. An active region is positioned in the sandwich to provide optical gain in response to the active region control signal. An optical absorber is positioned in the sandwich. The optical absorber has wavelength dependent absorption in response to the optical absorber control signal. The device of the invention may be utilized as an integrated detector, a self-pulsating laser, a high speed intracavity modulator, or an optical pick-up device.

Vertical-cavity surface-emitting laser with an intracavity quantum-well

A compact and cost-effective wavelength meter and photodetector (10) that can measure simultaneously both wavelength and intensity has two back-to-back photodiodes (12 and 14) with a wavelength dependent distributed Bragg reflector (DBR) (28) positioned in-between. The wavelength resolution of this device is 1 nm or less. Easy design and fabrication of the device provides for reliable and cost-effective manufacturing. Applications include instrumentation and wavelength-division-multiplexing (WDM) in optical communication systems.

Monolithic wavelength meter and photodetector using a wavelength

A network and method for routing optical signals through wavelength-coding of routing tags belonging to the optical signals. The routing tag preferably consists of one or more header pulses S.sub.i which are chosen from among header wavelengths .lambda..sub.hi. Preferably, the header wavelengths .lambda..sub.hi are different from wavelengths used by the data. The optical signal also has reset tag containing preferably one reset pulse R preferably having a unique reset wavelength .lambda..sub.r. The optical data is contained between the routing tag and the reset tag. The network has a splitter for dividing the optical signal into two or more split optical signals, which are copies of the original optical signal. A wavelength differentiating element is positioned in the path of one of the split optical signals to differentiate and preferably spatially resolve the header wavelengths of the header pulses. An opto-electronic control system, consisting of opto-electronic sensors and an electronic control circuit, generates electronic control signals based on the wavelength-coded information in the header tag. These electronic control signals are used to route one or more of the split optical signals through an optical switch. The network can be made up of one simple switch or a large number of complex switches.

Growing community of inventors

Danville, CA, United States of America

Kam-Yin Lau