Abstract: An array of electrostatically tiltable mirrors are formed in a MEMS structure. A first SOI wafer is etched to form an array of tiltable plates in the silicon device layer joined to the remainder of the wafer through pairs of torsion beams. A second SOI wafer is etched to form cavities corresponding to the tiltable plates. A ceramic multi-chip module (MCM) carrier is formed with multiple layers of wiring and electrodes corresponding to the tiltable plates. The two SOI wafers including their handle layers are bonded together. The handle layer of the second SOI is removed, and the bonded wafers are diced into chips. Each chip is bonded to a respective MCM carrier. Thereafter, the handle layer of the first SOI wafer is removed to release the tiltable mirror plates and the torsion beams. Electronic control chips may be bonded to the MCM carrier.

Abstract: Pulse-width modulation (PWM) control and drive circuitry particularly applicable to an array of electrostatic actuators formed in a micro electromechanical system (MEMS), such as used for optical switching. The high-voltage portion may be incorporated in an integrated circuit having drive cells vertically aligned with the MEMS elements. A control cell associated with each actuator includes a register selectively stored with a desired pulse width. A clocked counter distributes its outputs to all control cells. When the counter matches the register, a polarity signal corresponding to a drive clock is latched and controls the voltage applied to the electrostatic cell. The MEMS element may be a tiltable plate supported in its middle by a torsion beam. Complementary binary signals may drive two capacitors formed across the axis of the beam. The register and comparison logic for each cell may be formed by a content addressable memory.

Abstract: An optical cross connect, especially a wavelength cross connect, using free-space optics, a diffraction grating, and a micro electromechanical systems (MEMS) array of movable mirrors. A concentrator receives light from widely separated optical fibers and brings the beams together into a more closely spaced linear array. Free-space optics process all the beams. Front-end optics collimate the beams from the fibers and flatten their fields. The diffraction grating spectrally separates each beam into sub-beams. A long-focus lens focuses the sub-beams onto the 2-dimensional MEMS array. A fold mirror reflectively couples two such mirrors, whereby the switched signals propagate back through the same optics and are spectrally recombined onto the fibers. Other embodiments include white-color cross connects, multiple MEMS arrays, and parallel optics. Power dividers or wavelength interleavers can divide signals from the fibers, and multiple cross connects switch different wavelength groups.

Abstract: A multi-wavelength or white-light optical switch including an array of mirrors tiltable about two axes, both to control the switching and to provide variable power transmission through the switch, both for optimization and for power equalization between wavelength channels in a multi-wavelength signal. The output power of a channel is monitored, thereby allowing feedback adjustment of the transmitted power. The mirrors are preferably formed in a micro electromechanics system array to be tiltable in orthogonal directions and having electrostatically controlled tilting by two pairs of electrodes beneath the mirrors. Input power of the separate channels may also be monitored.

Abstract: A multiplexed analog control system for an micro electromechanical systems (MEMS) array of electrostatic actuators, such as tiltable mirrors in an optical switch. Each actuator includes a variable gap capacitor formed as part of the movable mechanical element. A hold capacitor is connected to each actuator capacitor, and a selectable high-voltage inverter connects them to provide a bipolar drive signal of 50% duty cycle. A single power digital controlled current source is connected to all the drive circuits to provide a high-power correction signal. Address decoders enable a selected one of the drive circuits to add or subtract the correction from the hold capacitor.

Abstract: Pulse-width modulation (PWM) control and drive circuitry particularly applicable to an array of electrostatic actuators formed in a micro electromechanical system (MEMS), such as used for optical switching. The high-voltage portion may be incorporated in an integrated circuit having drive cells vertically aligned with the MEMS elements. A control cell associated with each actuator includes a register selectively stored with a desired pulse width. A clocked counter distributes its outputs to all control cells. When the counter matches the register, a polarity signal corresponding to a drive clock is latched and controls the voltage applied to the electrostatic cell. The MEMS element may be a tiltable plate supported in its middle by a torsion beam. Complementary binary signals may drive two capacitors formed across the axis of the beam. The register and comparison logic for each cell may be formed by a content addressable memory.

Abstract: An optical cross connect, especially a wavelength cross connect, using free-space optics, a diffraction grating, and a micro electromechanical systems (MEMS) array of movable mirrors. A concentrator receives light from widely separated optical fibers and brings the beams together into a more closely spaced linear array. Free-space optics process all the beams. Front-end optics collimate the beams from the fibers and flatten their fields. The diffraction grating spectrally separates each beam into sub-beams. A long-focus lens focuses the sub-beams onto the 2-dimensional MEMS array. A fold mirror reflectively couples two such mirrors, whereby the switched signals propagate back through the same optics and are spectrally recombined onto the fibers. Other embodiments include white-color cross connects, multiple MEMS arrays, and parallel optics. Power dividers or wavelength interleavers can divide signals from the fibers, and multiple cross connects switch different wavelength groups.

Abstract: Pulse-width modulation (PWM) drive circuitry particularly applicable to an array of electrostatic actuators formed in a micro electromechanical system (MEMS), such as used for optical switching. A control cell associated with each actuator includes a register selectively stored with a desired pulse width. A clocked counter distributes its outputs to all control cells. When the counter matches the register, a polarity signal corresponding to a drive clock is latched and controls the voltage applied to the electrostatic cell. In a bipolar drive, one actuator electrode is driven by a drive clock; the other, by the latch. The MEMS element may be a tiltable plate supported in its middle by a torsion beam. Complementary binary signals may drive two capacitors formed across the axis of the beam. The register and comparison logic for each cell may be formed by a content addressable memory.