Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Disclosed is an apparatus and method for detecting whether rotatable MEMS elements are in the “on” or “off” position. Embodiments of the invention have application in devices switches that employ mirrors that move between an “on” or “off” position, wherein they reflect light from an input fiber into an output fiber in the “on” position, and allow the light to pass in the “off” 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 “on” or “off” 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.

Abstract: 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.

Abstract: 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.

Abstract: Cantilevered microstructure apparatus and methods are described. An exemplary cantilevered microstructure apparatus includes a base, a cantilever, and a stop. The cantilever may be coupled to the base through a flexure, so that the cantilever is movable between a first angular orientation and a second angular orientation. The stop may be configured to contact the bottom portion of the cantilever in a contact area when the cantilever is in the second angular orientation. Alternatively, the stop may be configured to contact the cantilever in a contact area sized so that, upon application of an electrostatic bias between the cantilever and the stop, a sufficient force holds the cantilever against the stop.

Abstract: An optical crossbar switch having refractive or reflective components for equalizing beam spreading and diffraction in all the connections. The optical fibers or waveguides coupled to the switch are not staggered, but are parallel as in a conventional fiber array. The refractive component is disposed between the switch and the input optical fibers. Preferably, a similar refractive component is disposed between the output optical fibers and the switch. The refractive component can be a stairstep block made of glass, silicon or silica. Light from each input fiber travels through a well-defined thickness of the stairstep block. Since the block has a refractive index greater than the surrounding atmosphere, the wavelength in reduced within the block, and beam spreading and diffraction are reduced.

Abstract: An optical switch module having a movable mirror disposed between two fixed mirrors. All three mirrors are aligned parallel to each other in a linear array to form a crossbar switch. The movable mirror moves between a first position and a second position to selectively couple optical signals between two inputs and two outputs. The basic switch module may be scaled up to form an apparatus that incorporates N movable mirrors and N+1 fixed mirrors, where N is an integer greater than zero. Such an apparatus can accommodate 2N fiber inputs and 2N fiber outputs, e.g., in an optical add/drop multiplexer (OADM). The parallel configuration of the switch module takes advantage of existing lens array and fiber V-groove technology to facilitate integration of the fibers and collimators in the module, thereby reducing the difficulty and cost associated with alignment, assembly, and packaging.

Abstract: 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.

Abstract: A micromirror for fast beam steering and method of fabricating the same. The micromirror of the present invention is lightweight and optically flat, and includes a tensile membrane that is stretched under high tension across a rigid single-crystal silicon support rib structure. A thin layer of gold may be deposited on the polysilicon membrane to improve reflectivity. The tensile stress in the membrane gives the micromirror a very high resonant frequency, thereby allowing the mirror to be scanned at high frequencies without exciting resonant nodes that may compromise the flatness of the optical surface and ruin its optical properties. The tensile stress also causes the optical surface to be stretched flat. The micromirror of the present invention may be actuated by a staggered torsional electrostatic combdrive.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A two-segment contact buried heterostructure (BH) laser is pumped by a current applied to its absorber contact from a source of high impedance on the order of 100K.OMEGA. or more. The parasitic resistance between the absorber contact and the gain contact is high on the order of 10K.OMEGA.. For a given absorber (bias) current the laser exhibits a relatively wide hysteresis on the order of 1 mA or more in the light vs. gain contact current. Such a laser is highly useful as a bistable optical element. The laser is also bistable with selected pump gain and absorber currents to exhibit a wide hysteresis of voltage across the absorber contact vs. relative amounts of light which is reflected back to the laser as feedback. The laser serve both as a light source and as a detector for reading out binary information stored as light reflective spots on a medium, e.g. a video disk.

Abstract: A magneto-optic modulator of the bounce-cavity type is disclosed wherein the mirrors that are attached to the garnet crystal to provide the reflections are multilayered dielectric mirrors. By polarizing the input beam such that its E vector is perpendicular to the plane of incidence substantially total reflection is achieved from the mirrors and all of the input beam emerges from the garnet crystal. A metal film deposited on a plane of the crystal that is perpendicular to the mirrors permits the establishment of a magnetic field that is substantially parallel to the reflected beams within the crystal. When the field is established by passing current through the film, much of the light is lost during each of the reflections since substantial amounts of the polarized light having polarizations in the plane of incidence are coupled through the dielectric mirrors. Hence the intensity of the output beam is modulated by the current in the metal film.