Abstract: A MEMS-based device to steer and manipulate beams of light traveling in free-space in an optical switch. The optical switch is based on a rotating vertical micro-mirror constructed on a surface of a substrate. At least one input optical fiber is arranged to direct at least one optical signal through free-space along a first optical path parallel to the surface of the substrate. A plurality of output optical fibers are arranged to receive the optical signal traveling through free-space along other optical paths not co-linear with the first optical path. At least one substantially vertical, rotating micro-mirror assembly is constructed on the substrate. The assembly includes a rotating micro-mirror with a vertical centerline and an axis of rotation both perpendicular to the surface, but not co-linear. The rotating micro-mirror is rotatable between a first position not in the first optical path and at least a second position redirecting the optical signal to one of the output optical fibers.

Abstract: A micro-mechanical device including a gimbaled micro-mirror position able by a one or more thermal actuators. The thermal actuators are not attached to the micro-mirror. Rather, the micro-mirror is retained to the substrate by one or more gimbals. The micrometer sized thermal actuators are capable of repeatable and rapid moving the micro-mirror out-of-plane to accurately and repeatably steer a beam of light.

Abstract: A micrometer sized, single-stage, vertical thermal actuator with controlled bending capable of repeatable and rapid movement of a micrometer-sized optical device off the surface of a substrate. The vertical thermal actuator is constructed on a surface of a substrate. At least one hot arm has a first end anchored to the surface and a free end located above the surface. A cold arm has a first end anchored to the surface and a free end. The cold arm is located above the hot arm relative to the surface. The cold arm is adapted to provide controlled bending near the first end thereof. A member mechanically and electrically couples the free ends of the hot and cold arms such that the actuator bends generally at the flexure so that the member moves away from the substrate when current is applied to at least the hot arm.

Abstract: A micrometer sized, single-stage, vertical thermal actuator with controlled bending capable of repeatable and rapid movement of a micrometer-sized optical device off the surface of a substrate. The vertical thermal actuator is constructed on a surface of a substrate. At least one hot arm has a first end anchored to the surface and a free end located above the surface. A cold arm has a first end anchored to the surface and a free end. The cold arm is located above the hot arm relative to the surface. The cold arm is adapted to provide controlled bending near the first end thereof. A member mechanically and electrically couples the free ends of the hot and cold arms such that the actuator bends generally at the flexure so that the member moves away from the substrate when current is applied to at least the hot arm.

Abstract: A micrometer sized, single-stage, horizontal and vertical thermal actuator capable of repeatable and rapid movement of a micrometer-sized optical device off the surface of a substrate. The horizontal and vertical thermal actuator is constructed on a surface of a substrate. At least one hot arm has a first end anchored to the surface and a free end located above the surface. A cold arm has a first end anchored to the surface and a free end. The cold arm is located above and laterally offset from the hot arm relative to the surface. The cold arm is adapted to provide controlled bending near the first end thereof. A member mechanically and electrically couples the free ends of the hot and cold arms such that the actuator exhibits horizontal and vertical displacement when current is applied to at least the hot arm.

Abstract: A MEMS-based device to steer and manipulate beams of light traveling in free-space in an optical switch. The optical switch is based on a rotating vertical micro-mirror constructed on a surface of a substrate. At least one input optical fiber is arranged to direct at least one optical signal through free-space along a first optical path parallel to the surface of the substrate. A plurality of output optical fibers are arranged to receive the optical signal traveling through free-space along other optical paths not co-linear with the first optical path. At least one substantially vertical, rotating micro-mirror assembly is constructed on the substrate. The assembly includes a rotating micro-mirror with a vertical centerline and an axis of rotation both perpendicular to the surface, but not co-linear. The rotating micro-mirror is rotatable between a first position not in the first optical path and at least a second position redirecting the optical signal to one of the output optical fibers.

Abstract: A micrometer sized, single-stage, vertical thermal actuator capable of repeatable and rapid movement of a micrometer-sized optical device off the surface of a substrate. The vertical thermal actuator is constructed on a surface of a substrate. At least one hot arm has a first end anchored to the surface and a free end located above the surface. A cold arm has a first end anchored to the surface and a free end. The cold arm is located above the hot arm relative to the surface. A member mechanically and electrically couples the free ends of the hot and cold arms such that the member moves away from the substrate when current is applied to at least the hot arm. The hot arm can optionally include a grounding tab to minimize thermal expansion of the cold arm.

Abstract: A homogeneous compositions containing a fluorinated solvent, hydrogen fluoride, and an optional co-solvent, and the use of these compositions for etching of microelectromechanical devices is described.

Abstract: A polarization mode separator separates the optical signal into a first polarized signal and a second differently polarized signal traveling along respective first and second paths. A first variable delay generator located along the first path is adapted to selectively provide a first propagation delay to the first polarized signal. The first variable delay generator includes at least two rotating micro-mirrors and one or more fixed mirrors constructed on a surface of a substrate. A controller is coupled to the first variable delay generator. The controller is adapted to monitor the polarization mode dispersion in the optical signal and to position the rotating micro-mirrors to direct the first polarized signal along one of the plurality of optical paths. A beam combiner combines the first and second signals to form an optical output signal substantially compensated for polarization mode dispersion.

Abstract: A micrometer sized, single-stage, horizontal and vertical thermal actuator capable of repeatable and rapid movement of a micrometer-sized optical device off the surface of a substrate. The horizontal and vertical thermal actuator is constructed on a surface of a substrate. At least one hot arm has a first end anchored to the surface and a free end located above the surface. A cold arm has a first end anchored to the surface and a free end. The cold arm is located above and laterally offset from the hot arm relative to the surface. The cold arm is adapted to provide controlled bending near the first end thereof. A member mechanically and electrically couples the free ends of the hot and cold arms such that the actuator exhibits horizontal and vertical displacement when current is applied to at least the hot arm.

Abstract: An apparatus for equalizing polarization mode dispersion in an optical signal traveling through an optical fiber. A polarization mode separator separates the optical signal into a first polarized signal and a second differently polarized signal traveling along respective first and second paths. A first variable delay generator located along the first path is adapted to selectively provide a first propagation delay to the first polarized signal. The first variable delay generator includes at least two rotating micro-mirrors and one or more fixed mirrors constructed on a surface of a substrate. The fixed mirrors include a plurality of optical paths of differing lengths adapted to optically couple with the two rotating micro-mirrors. A controller is coupled to the first variable delay generator. The controller is adapted to monitor the polarization mode dispersion in the optical signal and to position the rotating micro-mirrors to direct the first polarized signal along one of the plurality of optical paths.

Abstract: A micrometer sized multi-directional thermal actuator capable of repeatable and rapid displacement in a substantially horizontal direction, a substantially vertical direction, and/or a combination thereof. The multi-directional thermal actuator constructed on a surface of a substrate includes three or more beams each cantilevered from one or more anchors at a first end to extend generally parallel to the surface of the substrate. A member mechanically and electrically couples the distal ends of the beams. Application of current to a circuit comprising combinations of any two or more of the beams displaces the member in one of three or more non-parallel radial directions, respectively.

Abstract: Disclosed is candle filter assembly including a candle filter for the filtration of particulates from a fluid. The candle filter is constructed of ceramic fibers and includes a gimbal mount. The candle filter is pivotally supported, and is mounted so as to redirect axial compressive forces into compressive through wall compressive forces. Also disclosed is a filtration system including a plurality of such candle filter assemblies mounted in an enclosure.

Abstract: The present invention provides a method of making a shaped ceramic-ceramic composite articles, such as gas-fired radiant heat burner tubes, heat exchangers, flame dispersers, and other furnace elements, having a formed-on ceramic-ceramic composite thereon.

Abstract: A Doppler blood flow system and method in which an ultrasonic wave is reflected off of red blood cells in blood flowing in tubing. The reflected ultrasonic wave is digitally processed in the frequency domain. The flow rate of the blood is directly related to the average frequency of the Doppler signal. The typical Doppler signal is not a single frequency representing a single flow rate but is really an entire range of frequencies in which certain frequencies predominate which are indicated by increased amplitude of the signal when plotted in the frequency domain. The typical Doppler signal may actually have two "humps", one at a higher frequency which represents the actual information bearing content of the signal related to flow rate and one at a lower frequency which is caused by vibrations in the blood tubing system itself and could be caused by motor noise from the blood pump.

Abstract: A Doppler blood flow system and method in which an ultrasonic wave is reflected off of red blood cells in blood flowing in tubing. The reflected ultrasonic wave is digitally processed in the frequency domain. The flow rate of the blood is directly related to the average frequency of the Doppler signal. Because the Doppler blood flow system calculates flow rate solely on the basis of frequency, a special case exists at zero rate of flow where the received signal is not a valid Doppler flow signal, but rather purely noise. The noise at zero flow rate is random and will not have an average frequency which is unique to zero flow. The Doppler blood flow system and method must invoke a special case determination of when a zero flow condition exists in order to accurately provide a blood flow rate. The system utilizes a method of determining the rate of flow of a fluid containing particles flowing through a tube. An ultrasonic signal is transmitted through the tube at an oblique angle thereto.