Integrated Micromachines, Inc.

Northrop Grumman Systems Corporation

Northrop Corporation

Brent E Burns

Benedict B O'Brien

John A Geen

Weilong Tang

Tseng-Yang Hsu

Denny K Miu

Shuyun Wu

King L Hu

Viktoria Temesvary

Adrian C Ionescu

A fiber-optic microswitch is disclosed that includes a flexible mirror positioning structure including an outer fixed frame, a movable platform upon which a mirror is formed, and two or more resilient support members (e.g., monocrystalline silicon springs or torsion beams) connecting the movable platform to the fixed frame. Stationary fibers are mounted over the mirror. An electromagnetic drive mechanism is provided for positioning the movable platform relative to the fixed frame. The electromagnetic drive mechanism includes one or more coils formed on a drive substrate mounted under the monocrystalline structure, and one or more pole pieces that are mounted on the movable platform. Currents are selectively applied to the coils to generate attractive electromagnetic forces that pull the pole pieces, thereby causing the movable platform to move (e.g., tilt) relative to the fixed frame, thereby selectively directing light from one fiber to another. Various monocrystalline structures are disclosed.

Silicon bulk-micromachined electromagnetic fiber-optics bypass microswitch

The present invention is directed to a micro-switch assembly involving a magnetic latching mechanism. In one aspect of the present invention, it involves a micromachined structure that comprises an outer frame, an inner frame pivotally connected to the outer frame and rotates when an external electromagnetic force is applied, and a mechanism for latching the inner frame at a given angle of inclination relative to the outer frame. One embodiment of the present invention involves the use of a magnetic material, such as Permalloy, and permanent magnets to achieve the latching result. A Permalloy piece is attached to the inner frame of the micro-switch assembly and a magnet layer is attached to the outer frame. The magnetic force attracting the Permalloy piece and the magnet layer allows the latching of the two frames to occur in the absence of the external applied electromagnetic force. The use of this magnetic latching mechanism allows a reduction in the use of electric current to maintain a movable frame in a micromachined structure or a micro-switch assembly in a fixed position. It provides greater mechanical and optical stability and less energy consumption. In other embodiments, additional Permalloy pieces can be added to the outer frame to increase the magnetic field, so as to further reduce the electric current necessary for latching and unlatching the frames.

Latching mechanism for optical switches

This invention provides a very sensitive optical attenuator, which can be used to couple and attenuate optical signals between optical fibers with a wide range of attenuation level. Such an optical attenuator includes a flexible conductive membrane to be moved by an external force, such as electrostatic force, to achieve deformation of the conductive membrane. The conductive membrane can be formed, for example, by a vacuum deposited silicon nitride film. A thin metallic, conductive layer is then deposited on the flexible membrane to form a reflective mirror to receive and reflect incident optical signals. The semiconductor structure includes one or more spacing posts, with which the first structural member is to be joined and bonded. Electrodes are placed on the semiconductor structure in close proximity to the flexible membrane. At various areas of the semiconductor structure, additional spacing posts are added to cause deformation of the conductive membrane when a voltage is applied between the membrane and the electrodes on the semiconductor structure.

Micromachined voltage controlled optical attenuator

A planar masking process for multi-depth etching of a silicon wafer wherein more than one etch depth is photolithographically patterned prior to etching the wafer and while the wafer still has a planar surface. A plurality of layers of masking material are disposed on at least one of the top and bottom surfaces of the silicon wafer and various of these layers are patterned by selectively photolithographically patterning and removing regions of the layers to form masks for areas where different silicon etch depths are desired. After forming the masks, the wafer is etched to a first level and the outermost mask is removed by etching. The silicon wafer is then again etched to another level with the remaining masks in place. The uppermost mask of the remaining masks is removed and the silicon wafer is again etched to still another level. The process is repeated until the desired levels have been etched in the silicon wafer.

Planar masking for multi-depth silicon etching

An integrated rate and acceleration sensor includes at least one accelerometer formed from a substantially planar silicon body. The at least one micro-silicon accelerometer (MSA) includes a first frame and a proof mass suspended from the first frame by first flexures. The at least one accelerometer has an associated sensitive axis and an associated rate axis that is orthogonally disposed to the sensitive axis. The integrated sensor further includes structure for dithering or vibrating the proof mass along a dither axis that is disposed perpendicularly to both the rate and the sensitive axes. The dithering structure includes at least first and second interdigitated electrodes. Finger portions of the electrodes are disposed for exerting an electrostatic force upon a portion of the planar body in response to an oscillatory drive signal. The portion of the planar body has a plurality of linear grooves formed therein, the plurality of linear grooves being disposed in a parallel orientation with the finger portions. A vibrating accelerometer gyro (VAG) structure is constructed by micromachining techniques such that the linear momenta of two vibrating MSAs balance one another. A symmetrical disposition of the vibrating proof masses tends to balance the linear momenta of the MSAs, and increases the resonance amplification factor (Q).

Micromachined accelerometer gyroscope

A miniature accelerometer is fabricated using integrated circuit manufacturing and silicon micromachining techniques to form a closed loop, force balance sensor utilizing a silicon proofmass formed from and connected to a layer of silicon by a split flexure etched therein. The sensor circuitry detects AC signals coupled from the proofmass to a pair of electrodes formed on glass surfaces anodically bonded to the silicon layer. A DC restorative force is applied to the electrodes in response to the detected AC signals to balance acceleration forces applied to the proofmass. The sensor design is highly symmetrical.

Miniature silicon accelerometer and method

A spatial light modulator including a silicon backplate having an insulating layer and a standoff grid of insulating material deposited on the backplate to define an array of cells. An electrode is deposited in each cell on said backplate. A thin membrane of doped silicon is mounted to the standoff grid and over said array of cells and electrodes. Mirrors are laid on the membrane to create an array of reflective pixels over the array of cells. When an electrode is selectively charged the portion of the membrane overlying that cell is deflected by electrostatic attraction between the membrane and the electrode. Taken overall, a pattern is assumed by the array of pixels which corresponds to the state of the electrical signals placed on the electrodes. A vent hole formed in each cell from the electrode side of the backplate to the opposite side thereof for venting gas from the cell when said diaphragm is deflected, and grooves extend across the face of the backplate and over the cell to intersect the vent hole to assist in venting gas out of the cell and through the hole. The vent hole is preferably of a size and constructed for critical damping of the movement of the mass of the deflected diaphragm at said cell to control the movement caused by the electrostatic deflection. Flexures of reduced cross-section are formed in the diaphragm along a closed line extending around the inside perimeter of the stand off grid, so that said diaphragm moves more nearly in piston mode within the flexure.

Growing community of inventors

Rancho Palos Verdes, CA, United States of America

Brent E Burns