Abstract: The present invention provides methods, apparatus and systems for protecting connections between optical cross-connect switches and client equipment. A connection failure is detected, signaled, and a switch made by the client equipment and the optical cross-connect switch to a protection connection between them so as to minimize service interruption. An out-of-band channel or an in-band channel can be used to signal the connection failure.

Abstract: A micro-mirror strip assembly having a plurality of two-dimensional micro-mirror structures with improved deflection and other characteristics is presented. In the micro-mirror structures, electrodes for electrostatic deflection are disposed on conical or quasi-conical entities that are machined, attached or molded into a substrate. The electrodes are quartered approximately parallel to or offset by 45 degrees from rotational axes to form quadrants. Torsion sensors are provided along the axes of rotation to control deflection of the quadrant deflection electrodes.

Abstract: A micro-mirror strip assembly having a plurality of two-dimensional micro-mirror structures with improved deflection and other characteristics is presented. In the micro-mirror structures, electrodes for electrostatic deflection are disposed on conical or quasi-conical entities that are machined, attached or molded into a substrate. The electrodes are quartered approximately parallel to or offset by 45 degrees from rotational axes to form quadrants. Torsion sensors are provided along the axes of rotation to control deflection of the quadrant deflection electrodes.

Abstract: Methods, apparatus and systems for regenerating, monitoring and bridging optical signals through an optical cross-connect switch to provide increased reliability. A self testing method, apparatus and system for an optical cross-connect switch. An optical-to-electrical-to-optical converter (O/E/O) is provided in an optical cross-connect switch to provide optical-electrical-optical conversion. I/O port cards having an optical-to-electrical-to-optical converter are referred to as smart port cards while I/O port cards without an optical-to-electrical-to-optical converter are referred to as passive port cards. Test port/monitor cards are also provided for testing optical cross-connect switches. Methods, apparatus and systems for performing bridging, test access, and supporting redundant optical switch fabrics are also disclosed.

Abstract: In one embodiment, a scalable cross-connect switching system and its corresponding method perform a bridging operation by splitting the incoming light signal into at least a first bridged light signal and a second bridged light signal. The first bridged light signal has a power level equal to or substantially greater than a power level of the second bridged light signal. The disproportionate power levels provide low-loss bridging. Light signals based on these bridged light signals are routed through multiple switch fabrics which provide redundancy in case of failure by switching within the switch fabric. To detect failures, a test access port is configured for monitoring multiple optical paths.

Abstract: In general, an optical cross-connect switching system comprising a switch subsystem, an input/output (I/O) subsystem including a plurality of removable, I/O port modules, and a switch control subsystem featuring servo modules. These units collectively operate to provide optical data paths for routing of light signals without conversion from optical to electrical domains and back to optical. Also, the optical cross-connect switching system is scalable because the I/O port modules, servo modules and even features of the switch subsystem may be removed without disruption in system operation.

Abstract: A micro-mirror strip assembly having a plurality of two-dimensional micro-mirror structures with improved deflection and other characteristics is presented. In the micro-mirror structures, electrodes for electrostatic deflection are disposed on conical or quasi-conical entities that are machined, attached or molded into a substrate. The electrodes are quartered approximately parallel to or offset by 45 degrees from rotational axes to form quadrants. Torsion sensors are provided along the axes of rotation to control deflection of the quadrant deflection electrodes.

Abstract: A mechanism for reducing radial offset in a collimnated optical beam associated with an angled end fiber and minimizing an angular offset caused by collimator lens centration errors is presented. An angled end fiber is oriented in a supporting collimator so that the angled surface of the fiber is parallel to the collimator axis, thereby compensating for the radial offset. The angled end fiber is again so oriented after the angular-offset producing collimator lens rotation (used to determine the optical center of the lens) and the collimator lens is moved in a direction parallel to the collimator axis to provide a desired output focal position for the lens.

Abstract: A method for operating a monolithic, integrated, micromachined structure that includes a reference member and one or more dynamic members. Each dynamic member is supported from the reference member, either directly or indirectly, by torsion hinges. Supported in this way, each dynamic member exhibits a plurality of vibrational modes. Preferably, the structure is micromachined to establishes specified relationships between various pairs of vibrational modes. The method also includes applying force to each dynamic member that urges the member to rotate out of a rest position to a fixed particular angle.

Abstract: A fiber optic switch includes a fiber optic switching module that receives and fixes ends of optical fibers. The module includes numerous reflective light beam deflectors which may be selected as pairs for coupling a beam of light between a pair of optical fibers. The module also produces orientation signals from each deflector which indicate its orientation. A portcard included in the switch supplies drive signals to the module for orienting at least one deflector. The portcard also receives the orientation signals produced by that deflector together with coordinates that specify an orientation for the deflector. The portcard compares the received coordinates with the orientation signals received from the deflector and adjusts the drive signals supplied to the module to reduce any difference between the received coordinates and the orientation signals. The switch also employs optical alignment to precisely orient pairs of deflectors coupling a beam of light between optical fibers.

Abstract: A method for fabricating an integrated, micromachined structure, such as a torsional scanner, that includes a reference member, such as a frame, a pair of torsion hinges, and a dynamic member that is coupled to the reference member by the torsion hinges. The method includes providing a wafer that has been formed from silicon material, and that has both a frontside and a backside. A membrane is formed in the wafer by etching a cavity in the silicon material from the backside of the wafer. The method also includes establishing a pattern that defines the mirror surface and the torsion hinges on the frontside of the wafer at the membrane formed therein. The frontside of the wafer is processed to form therein the dynamic member and the torsion hinges that support the dynamic member for rotation about the axis.

Abstract: A monolithically fabricated micromachined structure (52) couples a reference frame (56) to a dynamic plate (58) or second frame for rotation of the plate (58) or second frame with respect to the reference frame (56). Performance of torsional oscillators or scanners (52) benefits greatly by coupling the frame (56) to the plate (58) or second frame with torsional flexure hinges (56) rather than torsion bars (54). Appendages (122), tethers (142) or an improved drive circuit enhance electrostatic drive stability of torsional oscillators (52). Wide and thin torsional flexure hinges (96) and isotopically pure silicon enhance thermal conductivity between the plate (58) and the frame (56). Dampening material bridging slots (232) adjacent to torsional flexure hinges (96) drastically reduce the dynamic member's Q. A widened section (252) of narrow torsional flexure hinges (96) permit inclusion of a torsion sensor (108). A dynamic member (58) that includes an actuator portion (302) performs light beam switching.

Abstract: A topographic head for profilometry and AFM supports a central paddle by coaxial torsion bars projecting inward from an outer frame. A tip projects from the paddle distal from the bars. The topographic head's frame, bars and paddle are monolithically fabricated by micromachining from a semiconductor wafer. The torsion bars preferably include an integrated paddle rotation sensor. The topographic head may be carried on an XYZ stage for X, Y and Z axis translation. In a preferred embodiment, the XYZ stage is also monolithically fabricated by micromachining from a semiconductor wafer with a fixed outer base that is coupled to an X-axis stage via a plurality of flexures, and with the X-axis stage supporting a Y-axis stage also via a plurality of flexures.

Abstract: A document transport for a scanner (100) has a flexible, elongated finger (226) disposed adjacent to a document (134), and a force applied to the finger (226) urges teeth (233) on the finger (226) into contact with the document (134) which urges the document (134) along a path through the scanner (100). A piezoelectric plate (222), which applies the force to the finger (226), requires only a small amount of electrical power. To traverse the scanner (100), a document (134) may also be manually fed along a guide (272). First and second speed-sensing detectors (276a and 276b), disposed along the path traversed by the document (134), permit the scanner (100) to determine a speed at which the manually fed document (134) traverses the scanner (100). To conserve electrical energy, the scanner (100) also includes a document-presence detector (274) for activating the scanner (100) when a document (134) to be scanned is present.

Abstract: A beam (38) of electromagnetic radiation deflected by a moving mirror plate (56) of a micromachined scanner (54) produces a two dimensional ("2D") raster (132) on a scanned surface (28) of a block (34). The block (34) is transparent to electro-magnetic radiation of pre-established wavelengths. A radiation inlet-face (36) of the block (34) admits the beam (38) that then impinges on the scanned surface (28) to exit the block (34) through a radiation outlet-face (42). After exiting the block (34), the beam (38) impinges upon a radiation detector (142). Total internal reflection ("TIR") of the beam (38) from the scanned surface (28) at fingerprint valleys and frustration of TIR at fingerprint ridges causes the radiation detector (142) to produce a time-varying electrical signal that represents the fingerprint. The scanned surface (28) may be formed by a patch (302) of resilient material, that may be tinted to be transparent only at the pre-established wavelength of the electro-magnetic radiation.

Abstract: A document transport for a scanner (100) has a flexible, elongated finger (226) disposed adjacent to a document (134), and a force applied to the finger (226) urges teeth (233) on the finger (226) into contact with the document (134) which urges the document (134) along a path through the scanner (100). A piezoelectric plate (222), which applies the force to the finger (226), requires only a small amount of electrical power. To traverse the scanner (100), a document (134) may also be manually fed along a guide (272). First and second speed-sensing detectors (276a and 276b), disposed along the path traversed by the document (134), permit the scanner (100) to determine a speed at which the manually fed document (134) traverses the scanner (100). To conserve electrical energy, the scanner (100) also includes a document-presence detector (274) for activating the scanner (100) when a document (134) to be scanned is present.

Abstract: Two torsion bars project from a reference member to support at least one plate or frame-shaped first dynamic member for rotation about an axis of the torsion bars. In one embodiment, a frame-shaped first dynamic member and a second pair of torsion bars, oriented non-parallel to the first torsion bars, support a second dynamic member for rotation about an axis that is collinear with the second pair of torsion bars. The vibrational frequency of the principal torsional vibrational mode of the dynamic members are respectively lower by at least 20% than the vibrational frequency of any other vibrational mode thereof. Either an electrostatic or electromagnetic drive means imparts rotary motion to the dynamic members about the collinear torsion bar axis(es). The reference member, the torsion bars and the dynamic member(s) are all monolithically fabricated from a stress-free semiconductor layer of a silicon substrate.

Abstract: An improved micromachined structure used for beam scanners, gyroscopes, etc. includes a reference member from which project a first pair of axially aligned torsion bars. A first dynamic member, coupled to and supported from the reference member by the torsion bars, oscillates in one-dimension about the torsion bar's axis. A second dynamic member may be supported from the first dynamic member by a second pair of axially aligned torsion bars for two-dimensional oscillation. The dynamic members respectively exhibit a plurality of vibrational modes each having a frequency and a Q. The improvement includes means for altering a characteristic of the dynamic member's frequency and Q. Coupling between dynamic members permits altering the second dynamic member's frequency and Q by techniques applied to the first dynamic member. Some techniques disclosed also increase oscillation amplitude or reduce driving voltage, and also increase mechanical ruggedness of the structure.

Abstract: A topographic head for profilometry and AFM supports a central paddle by coaxial torsion bars projecting inward from an outer frame. A tip projects from the paddle distal from the bars. The torsion bars include an integrated paddle rotation sensor. A XY stage may carry the topographic head for X and Y axis translation. The XYZ stage's fixed outer base is coupled to an X-axis stage via a plurality of flexures. The X-axis stage is coupled to a Y-axis stage also via a plurality of flexures. One of each set of flexures includes a shear stress sensor. A Z-axis stage may also be included to provide an integrated XYZ scanning stage. The topographic head's frame, bars and paddle, and the XYZ stage's stage-base, X-axis, Y-axis and Z-axis stages, and flexures are respectively monolithically fabricated by micromachining from a semiconductor wafer.

Abstract: A compact medium scanner (100) scans a surface (132) of a medium (134) with a beam of light (106). A medium transport mechanism (202, 206) advances the surface along a medium transport path through a scanning station. A light source (104) produces a collimated beam of light (106) that impinges upon a mirror plate (112) of a micromachined torsional scanner (108). A pair of coaxially aligned torsion bars (304) support the mirror plate (112) within the torsional scanner (108). A mirror-surface drive means (306, 312) rotates the mirror plate (112) about the torsion bars (304). A single reciprocation of the mirror plate (112) by the drive means (306, 312) deflects the beam of light (106) over a fan-shaped region having a virtually fixed vertex (128) on the mirror plate (112). Scanner optics (116, 122) direct the fan-shaped region beam of light (106) onto the surface (132) of the medium (134) then present in the scanning station to thereby scan across the medium (134) with the beam of light (106).