Abstract: Disclosed is herein an optical switch, which has advantages of an MEMS optical switch and a waveguide optical switch including a small electric power consumption, an easy packaging process, and a fast switching speed. The optical switch includes an input waveguide connected to an input optical fiber through which an optical signal is inputted, and a plurality of output waveguides connected to a plurality of output optical fibers through which the optical signal is outputted. An actuator is positioned between the input waveguide and the output waveguides, and has an MEMS structure including a fixed part and a moving part connected to the fixed part by a spring to move by a predetermined force.

Abstract: As the traffic volume carried by telecommunication networks has been rapidly increased as a result of the bandwidth-intensive applications such as Internet access, electronic commerce multimedia applications, and distributed computing, it is imperative to utilize the optical network for backbone, metropolitan, and local area networks. The optical networks employing optical fibers as the transmission medium have exhibited a superior performance/cost ratio for both long-haul and short-haul routes and the emerging dense wavelength division multiplexing (DWDM)/all-optical networks have shown a promising potential to improve speed, capacity and connectivity of optical telecommunication networks. The present invention provides Micro-Opto-Electro-Mechanical Waveguide Switch (MOEM-WS) by integrating MEMS actuators and micromachined PLCs on the same substrate.

Abstract: Disclosed are a multi-channel optical switch and a method for manufacturing the same. The multi-channel optical switch includes a supporter; an input terminal optical fiber fixed to the supporter for inputting an optical signal to be switched therethrough; multiple output terminal optical fibers fixed to the supporter for outputting the optical signal inputted through the input terminal optical fiber therethrough; multiple micro mirrors for reflecting the optical signal inputted through the input terminal optical fiber and then for directing the optical signal to a designated output terminal optical fiber among the multiple output terminal optical fibers; and multiple actuators respectively connected to the micro mirrors for adjusting the positions of the micro mirrors so that the optical signal is reflected by the micro mirrors.

Abstract: To provide a mechanical optical switch including a movable optical fiber which can be elastically deformed and a fixed optical fiber, open ends of the movable optical fiber and the fixed optical fiber facing each other via an optical gap, which switches an optical path by moving the open end of the movable optical fiber relatively to the open end of the fixed optical fiber with an electromagnetic actuator. The fixed optical fiber is held by a fixed holder at a point close to its open end. The movable optical fiber is supported by another fixed holder at a point distant from its open end, and a movable holder holding the movable optical fiber at a point close to its open end reciprocates relatively to the fixed holder holding the fixed optical fiber. An electromagnetic actuator is located in an area on the movable optical fiber side from the open end of the movable optical fiber. Preferably, it is provided between the open end of the movable optical fiber and the latter fixed holder.

Abstract: An optical switch includes a plurality of optical fibers arrayed at equal intervals and in parallel, each optical fiber having a central axis and having an end surface on one side of the optical switch. A single lens has a focal length and a central axis parallel to each fiber central axis, the lens disposed away from the fiber end surface at a distance corresponding to the focal length of the lens. A first mirror has a reflection surface perpendicular to the lens central axis, the first mirror removably disposed at a first position on the other side of the optical switch. A second mirror has a reflection surface inclined from the lens central axis, the second mirror removably disposed at the first position. One of the first and second mirrors is selectively disposed at the first position.

Abstract: The present invention provides improved optical switches in which only a spatial beam shifting of a small free space offset is required to direct optical pathways between plural fiber ports. This is achieved by spacing two fibers closely and collimating their beams with one imaging lens for compactness. Advantageously, the inventive switches incorporate beam correcting devices to render the beam propagations parallel, allowing light beams to be efficiently coupled into two fibers that share a single lens with substantially improved stability.

Abstract: An optical switch is provided with an optical-fiber-arraying-member 1 in which a plurality of optical fiber fixing grooves 1a extending along radial directions of a virtual circle are radially formed in a predetermined surface of a base material, a plurality of array-side optical fibers 2 arrayed in the plurality of optical fiber fixing grooves 1a of the optical-fiber-arraying-member 1, and a moving-side optical fiber 4 to be selectively optically connected to either of the plurality of array-side optical fibers 2; the moving-side optical fiber 4 and the optical-fiber-arraying-member 1 are rotated relative to each other about a center axis 1o of the virtual circle, and the moving-side optical fiber 4 is selectively optically connected to the array-side optical fiber 2 selected.

Abstract: A MEMS optical switch includes a movable cantilevered beam with a waveguide corresponding to one port of the switch. The beam is designed for in-plane motion and can be deflected, e.g., using a three-electrode motion actuator having one electrode on each side of the beam, which itself acts as the third electrode. The beam moves toward a side electrode in response to a voltage difference applied between the beam and that electrode. The beam has two terminal positions, each defined by a stopper. At each terminal position, a bumper portion of the beam is pushed against a corresponding stopper, which aligns the waveguide in the beam with one of two stationary waveguides, each corresponding to a port of the switch. The MEMS switch may be fabricated using a single silicon-on-insulator (SOI) wafer.

Abstract: This application describes an optical switching method for selectively directing an input beam to at least one of two output channels. The input beam impinges on a polarizing beam splitting surface, splitting the input beam into two beam components of different polarizations propagating along different optical paths. These beam components then pass through a controllable polarization rotating medium which selectively affects the polarization of each of the beam components. The beam components are then directed back onto the polarizing beam splitting surface again, producing at least one output beam which propagates toward at least one selected output channel, depending on the state of the medium. The polarizing beam splitting surface is fabricated on a block of the controllable polarization rotating medium, and the input beam also passes through the medium before being split into two beam components by the polarizing beam splitting surface.

Abstract: A method and apparatus for multiplexing and demultiplexing optical signals. The apparatus includes first and second optical waveguides coupled via an optical coupler. The optical coupler has a coupling waveguide and an optical switching wedge attached to a piezoelectric actuator. In operation, first and second optical signals are received by the first and second optical waveguides, respectively. If the signals are to be combined, the optical switching wedge is moved to a first position where it is optically coupled to the first optical waveguide. The first optical signal is then transmitted, via the coupling waveguide, to the second optical waveguide, where it is combined with the second optical signal. If the signals are not to be combined, the optical switching wedge is moved to a second position where it is optically uncoupled from the first optical waveguide.

Abstract: A 1×N or N×1 optical switch based on a plurality of movable MEMS-created platforms, each carrying a light guiding structure such as a waveguide, where the position of the platforms determines which optical path is connected through the optical switch. The MEMS-created platforms are formed integral with the substrate of the optical switch. The waveguides residing on the movable platforms gradually change the direction of the optical signal in order to minimize losses. The movable platforms can move linearly or rotationally, for example. Also described is a method for fabricating such an optical switch and its components by etching from the bottom of the substrate and through the oxide.

Abstract: A method of monitoring fiber optic circuits. Included is manipulating a first switch between a first state, with first connection points optically linked along a first optical signal pathway and second connection points optically linked along a second optical signal pathway, and a second loopback state, with the first and second connection points of a first pair of connection locations in communication along a path along a portion of the first and second optical signal pathways. With the first switch in the first state, a third pair of connection locations are linked to the first optical pathway and the optical throughout observed. The third pair of connection locations are then linked to the second optical pathway and the optical throughout observed. These steps are repeated as long as the first and second optical pathways transmit the optical throughout normally.

Abstract: A device and method for detecting rotational drift of mirror elements in a MEMS tilt mirror array used in an optical crossconnect. The optical crossconnect directs optical signals from an input fiber to an output fiber along an optical path by rotatably positioning mirror elements in desired positions. A monitoring device disposed outside of the optical path is used to obtain images of the MEMS array or to transmit and receive a test signal through the crossconnect for detecting the presence of mirror element drift.

Abstract: An optical micro-electro-mechanical system (MEMS) switch is disclosed. In a preferred embodiment the optical MEMS switch is used as an M×N optical signal switching system. The optical MEMS switch comprises a plurality of optical waveguides formed on a cantilever beam platform for switching optical states wherein the state of the optical switch is changed by a system of drive and latch actuators. The optical MEMS device utilizes a latching mechanism in association with a thermal drive actuator for aligning the cantilever beam platform. In use the optical MEMS device may be integrated with other optical components to form planar light circuits (PLCs). When switches and PLCs are integrated together on a silicon chip, compact higher functionality devices, such as Reconfigurable Optical Add-Drop Multiplexers (ROADMs), may be fabricated.

Abstract: An optical switch element is described, which includes a fixed layer disposed outwardly from a substrate and a movable mirror assembly disposed outwardly from the fixed layer. The moveable mirror assembly is operable to move relative to the fixed layer responsive to a voltage applied to the movable mirror assembly. In a particular embodiment, the movable mirror assembly includes an inner strip spaced apart from the fixed layer by a first distance and an outer strip disposed approximately adjacent to the inner strip and spaced apart from the fixed layer by a second distance which is greater than the first distance. The optical transmission of the optical switch element changes depending on the position of the movable mirror assembly.

Abstract: An optical switch (10) includes an input device (11), a reflection output device (12), a transmission output device (13), a prism (2) and a rotation device (3). The input and reflection output devices are rotatable around the prism between a first position and a second position. The prism has a reflective surface (21) to effect optical switching. When the input and reflection output devices are at a first position, an input light beam from the input device passes through the reflective surface of the prism, and is output through the transmission output device. When the input and reflection output devices are at a second position, the input light beam from the input device is incident on the reflective surface of the prism at an angle which is equal to or larger than a critical angle of the prism. The input light beam is totally reflected by the reflective surface of the prism and is output through the reflection output device.

Abstract: An opto-mechanical switching device for selectively switching an optical input between a plurality of output fibers. The opto-mechanical switching device includes a re-directing fiber adapted to receive the optical input. The re-directing fiber is disposed within a re-directing fiber housing. The re-directing fiber housing is selectively positionable via a stepper motor to transmit the optical input to a predetermined one of the plurality of output fibers. A method for switching an optical input between a plurality of output fibers is also provided.

Abstract: An optical switching element has a movable optically transmissive microstructure to change the optical paths of the optical signals. The movable microstructure is “optically transmissive” because it includes structures such as waveguides and waveguide networks which transmit optical signals. The apparatus uses MEMS and micromachining technology to build an optical switch having an optically transmissive microstructure which moves from one position to another position in a direction (e.g., laterally, vertically, rotationally) such that incoming optical signals align over a small air gap with different waveguides, or with different inputs to the waveguides, depending on the position of the movable microstructure. As a result, the optical signals travel different optical paths (e.g., straight pass through or cross over) depending on the position of the movable microstructure.

Abstract: In order to monitor a large number of transmission paths, it is necessary to provide an optical coupling system for each path and dispose a photo detector to monitor the output thereof, or it is necessary to use a means for switching optical coupling. In the former case, there is a problem that the number of components for constituting an optical monitor increases and a signal processing system for monitoring the transmission paths as a whole is complicated. Further, in the latter case, there is another problem that optical coupling has to be maintained whenever the optical path is switched and that a long time is required for inspection when the number of paths is large.

Abstract: A method and apparatus for optical switching is described wherein a first optical input/output port and plurality of second optical input/output ports are coupled using an optical guiding assembly. An optical signal may thereby be movably directed between the first input/output port and a selected one of the second optical input/output ports. The optical guiding assembly includes a optical micro-element assembly and an actuator assembly which moveably directs the microlens assembly to a predetermined position corresponding to the selected one of the input/output ports. The actuator assembly includes a comb drive and the optical micro-element assembly includes an etched lens, a ball lens, a mirror, or the like.

Abstract: This invention relates to an optical switch comprising:

Abstract: A first waveguide holding member has a first transverse surface region and a first optical waveguide having an end terminating at the first transverse surface region. A second waveguide holding member has a second transverse surface region which confronts the first transverse surface region of the first waveguide holding member and a second optical waveguide having an end terminating at the second transverse surface region. A guide member is operatively coupled to the first and second waveguide holding members and guides the first waveguide holding member in a transverse direction relative to the second waveguide holding member so as to selectively optically couple and decouple the ends of the first and second optical waveguides.

Abstract: This invention provides a transparent, paramagnetic polymer composition in which a polymer is complexed with sufficient rare earth ions, particularly ions selected from ions in the group of elements 64-69, to provide a polymer with a magnetic mass susceptibility greater than 20×10−6 emu/g measured at 298° K. This invention provides optically responsive devices that employ these transparent, paramagnetic polymers as an element that is responsive to a magnetic field and a means for providing magnetic field. This invention provides transparent labels or markings employing these transparent, paramagnetic polymers.

Abstract: A MEMS optical switch includes a movable cantilevered beam with a waveguide corresponding to one port of the switch. The beam is designed for in-plane motion and can be deflected, e.g., using a three-electrode motion actuator having one electrode on each side of the beam, which itself acts as the third electrode. The beam moves toward a side electrode in response to a voltage difference applied between the beam and that electrode. The beam has two terminal positions, each defined by a stopper. At each terminal position, a bumper portion of the beam is pushed against a corresponding stopper, which aligns the waveguide in the beam with one of two stationary waveguides, each corresponding to a port of the switch. The MEMS switch may be fabricated using a single silicon-on-insulator (SOI) wafer.

Abstract: An optical module controls its output characteristics electrically and an optical switch constitutes the optical module. An optical waveguide circuit (PLC) and an electronic circuit (IC) for driving the PLC are mounted on the same substrate. The IC is composed of a bare chip to be molded afterward. Wiring of the IC is grouped and integrated on the PLC substrate to achieve higher density and miniaturization of the optical module.

Abstract: A magneto-optical switch includes a birefringent crystal that receives a light beam, a half-wave plate pair that receives the light beam from the birefringent crystal, a Faraday rotator that receive the light beam from the half-wave plate, a prism that receives the light beam from the Faraday rotator, and a reflective surface that receives the light beam from the Faraday rotator. The Faraday rotator receives an electromagnetic field to change the polarization of the light beam as it passes through the Faraday rotator.

Abstract: An electrooptical deflector is presented. The electrooptical deflector includes a material that has a different refractive index for different polarization states and changes its refractive index in response to voltage (e.g., lithium niobate or lithium tantalite). Inside the material is a poled region that includes triangularly-shaped prisms, each of which affects the direction in which an incident light beam propagates. When a light beam of a known polarization state propagates through the material, its direction of propagation (i.e., the amount of deflection) is controlled by a voltage applied to the poled region and the size and number of the prisms in the material.

Abstract: An optical switching system that switches the path of an optical signal by moving a microstructure onto which a light-guiding structure is mounted. The microstructure is formed by a MEMs and semiconductor process to be integral to the substrate. The light-guiding structure may include waveguides. The microstructure moves from one position to another position (e.g., laterally, vertically, rotationally) such that incoming optical signals align over a small air gap to different optical paths, depending on the position of the movable microstructure. As a result, the optical signal propagate along different optical paths (e.g., straight pass through or cross over) depending on the position of the movable microstructure. The optical paths have a large radii of curvature so as to change the direction of the optical signal gradually, thereby reducing insertion losses.

Abstract: A 1×N optical switch includes an input fiber collimator, an x-y scanning device including two perpendicular galvanometer-driven rotatable mirrors, and a 2-D array of output fiber collimators arranged over an output surface so as to be aligned with a corresponding ray extending from the x-y scanning device. Each of the output fiber collimators corresponds to a unique pair of rotation angles of the two mirrors. The output surface can have a spherical curvature, or a curvature which accounts for the dependency of optical path on the angles of the two mirrors. The switch allows improved switching speeds, accuracy, and reduced and uniform insertion losses. The architecture can be used for N×M switches and N×M cross-connects.

Abstract: The present invention provides an improved optical wavelength switch in which no mechanical movement is required to direct optical pathways between several fiber ports. The inventive three-fiber port device divides incoming optical signals into two subsets of spectra and selectively directs them into two output ports in response to an electrical control signal. In the inventive switch, an optical signal is spatially split into two polarized beams, by a birefringent element, which thereafter pass through a series polarization rotation elements and recombine into output fibers, achieving polarization independent operation. Advantageously, the inventive switch incorporates two-stage polarization rotations to improve isolation depth, as well as temperature and wavelength independence. The invention also incorporates light bending devices to allow two fibers to be coupled to the light beams via a single lens, thereby achieving small beam separation for compactness.

Abstract: Disclosed are devices and methods for switching transmission of light from one optical fiber to another. A steerable fiber has an end in a capsule, as do one or more cooperating fibers. Initially the steerable fiber is at a rest position, from where it couples light into one of the cooperating fibers. The end of the steerable fiber includes an armature that moves in response to applied magnetic fields. Then a magnetic field is generated selectively, and a pair of pole pieces transfers it to a location inside the capsule, which is close to the armature. Thus the end of the steerable fiber is moved to another position, from where it couples light into the other cooperating fiber.

Abstract: A switch for optically coupling a first optical channel to a selected one of a plurality of second optical channels includes a frame that defines a central passage, through which a beam coupled to the first optical channel may pass, and a plurality of peripheral passages, through which a beam coupled to a selected second optical channel may pass. A rotational object is capable of rotating about an axis. A beam redirector allows a first optical path to be optically coupled to a second optical path extending from a preselected position adjacent the peripheral area of the rotational object. A turning mechanism causes the rotational object to rotate to a position where the second optical path is in alignment with the selected one of the plurality of second optical channels.

Abstract: An optical switch is provided with an optical-fiber-arraying-member 1 in which a plurality of optical fiber fixing grooves 1a extending along radial directions of a virtual circle are radially formed in a predetermined surface of a base material, a plurality of array-side optical fibers 2 arrayed in the plurality of optical fiber fixing grooves 1a of the optical-fiber-arraying-member 1, and a moving-side optical fiber 4 to be selectively optically connected to either of the plurality of array-side optical fibers 2; the moving-side optical fiber 4 and the optical-fiber-arraying-member 1 are rotated relative to each other about a center axis 1o of the virtual circle, and the moving-side optical fiber 4 is selectively optically connected to the array-side optical fiber 2 selected.

Abstract: An optical spatial switch with perpendicular states and capability of high-speed operation in the range of about 100 Gb/sec is provided. The switch is made of n-i-p semiconductor waveguides of, for example, GaInAs/InP for operation at 1.55 &mgr;m wavelength or PbTe for operation at 3.39 &mgr;m in the form of multiquantum wells grown with a boundary plane with air formed as an exponential spiral. The waveguide claddings may be of n and p doped layers, with the core of i-type quantum wells separated by barriers. The waveguides of ports of incidence and reflection are made to be at critical (Brewester) angle of semiconductor/air interface for the case of decreasing (or increasing) refractive index due to the application of voltage and the port of transmission waveguide in the form of, for example an optical fiber, brought close to the boundary and aligned at the Brewester angle in the air. The hot and ground electrodes are made so that their edges are aligned to the curved semiconductor/air boundary.

Abstract: A method and system for providing an optical switch is described. The method and system include providing a triple fiber collimator, a beam deflector and a reflector. The triple fiber collimator is for receiving an optical signal from a first fiber and outputting the optical signal to a second fiber or a third fiber. The beam deflector has a first portion and a second portion. The beam deflector resides between the reflector and the triple fiber collimator. The optical signal travels through the first portion of the beam deflector, is reflected by the reflector and is output over the second fiber when the beam deflector is in a first position. The optical signal travels through the second portion of the beam deflector, is reflected by the reflector and is output over the third fiber when the beam deflector is in a second position.

Abstract: An optical switch (1) for switching light beams between one input optical fiber (21) and a plurality of output optical fibers (31) has a first port (2), a second port (3) and a switching element (4) between the first and second ports. The input port aligns with the input optical fiber and collimates input light beams. The output port aligns with the output fibers and decollimates output light beams. The switching element includes at least one rotatable optical element (41) for deflecting the light beams and a holder (42) for containing the rotatable optical elements. The rotatable optical element is rotatable among a plurality of positions, whereby, when the optical element is in different positions, the light beams from the input optical fiber are switched to different output fibers, respectively.

Abstract: An optical switch (10) includes an input device (11), a reflection output device (12), a transmission output device (13), a prism (2) and a rotation device (3). The input and reflection output devices are rotatable around the prism between a first position and a second position. The prism has a reflective surface (21) to effect optical switching. When the input and reflection output devices are at a first position, an input light beam from the input device passes through the reflective surface of the prism, and is output through the transmission output device. When the input and reflection output devices are at a second position, the input light beam from the input device is incident on the reflective surface of the prism at an angle which is equal to or larger than a critical angle of the prism. The input light beam is totally reflected by the reflective surface of the prism and is output through the reflection output device.

Abstract: In a digital optical switch, an input waveguide and two output waveguides form a Y-shaped splitter or switch. Electrodes are positioned on each output waveguide at the junction with the input waveguide. The electrodes extend as narrow strips across the waveguides. The inner edges of the electrodes are curved to form a smooth continuation profile to the signal paths to reduce losses.

Abstract: There is described a switching device comprising a mobile element (2) that is able to at least move back and forth along a defined trajectory between a zero position (O) and at least one predetermined switching position (A, B), an elastic member (3, 30, 32) connecting the mobile element to a base (4) and at least one stationary actuating electrode (5, 6) located in the vicinity of the predetermined switching position for producing electrostatic forces to cause the mobile element to move to and/or away from the predetermined switching position. The stationary actuating electrode is disposed to act on at least one edge (20a) of the mobile element which is substantially parallel to the mobile element's trajectory.

Abstract: An optical switch for switching an incoming light signal to one of a number of output ports in a polarization independent manner. The optical switch includes a walk-off device, and a compensator which compensates for walk-off distance variations of two polarized beams, with orthogonal polarization directions, associated with the walk-off device.

Abstract: A mechanical optical switch provides an active switching mechanism and an active latching mechanism that are both actuated by piezoelectric elements. The switching mechanism includes a switching frame at which fiber ends are attached to be switched along an opposing array of fixed fiber ends. The active latching mechanism provides for a fast switching of the switching mechanism and a reliable holding of the switching positions. The elements of the switching mechanism and the latching mechanism are monolithically fabricated from a wafer. The piezoelectric elements are integrated by bonding. The switch is substantially free of gliding friction, which reduces switching forces and makes the switch highly reliable over an extended lifetime.

Abstract: A fiber-optic switch uses a fiber-optic switching element in which a moving fiber (1) is positioned by a switching body (2) on a first stop (3) in front of a first fiber (4) which is arranged in a fixed position, or on a second stop (5) in front of a second fiber (6) which is arranged in a fixed position, with the moving fibers (1) being moved with respect to the first or second stop (3, 5) by the switching body (2) for positioning, and being pressed flat against the first or second stop (3, 5).

Abstract: A fiber optic switch with a plurality of switches, each having one input and N outputs, the switches are arranged and oriented relative to each other so that the input of a switch is in line with the outputs of any adjacent switches of the plurality of switches, wherein each switch includes controllable mirror and has a solid state actuator to directly control the mirror, this facilitating selection of one of a plurality of outputs.

Abstract: The present invention provides improved optical switches in which only a spatial beam shifting of a small free space offset is required to direct optical pathways between plural fiber ports. This is achieved by spacing two fibers closely and collimating their beams with one imaging lens for compactness. Advantageously, the inventive switches incorporate beam correcting devices to render the beam propagations parallel, allowing light beams to be efficiently coupled into two fibers that sharing a single lens with substantially improved stability.

Abstract: The present invention comprises apparatuses and methods, for routing optical communication signals over all DWDM wavelength channels. Incoming wavelength channels are separated into a plurality of sub-groups having a smaller optical bandwidth. Wavelength channels within each sub-group are then acted upon independently by a filter, or switch, tunable and operable over the bandwidth of each sub-group. The invention may be embodied in a plurality of dynamic wavelength routing circuits including 1×N and N×N circuits. The 1×N circuit embodiments may be used when the filter free-spectral range is smaller than the full DWDM bandwidth. These embodiments are less complicated than the N×N circuit embodiments, but do not provide the same routing bandwidth. The N×N circuit embodiments may be used to route the full DWDM bandwidth and may be used for other routing operations having large bandwidth demand.

Abstract: An optical switch for selectively coupling the free end of an input fiber to the free ends of one of two output fibers includes a fiber stabilizing guide. Each of the output fibers is adhesively fixed within a v-groove of an output alignment block. The output alignment blocks are held in stacked relationship within a housing with their v-grooves upturned. An input alignment block having an inverted v-groove within its bottom surface is provided for guiding the input optical fiber, upon switching, toward engagement with the output fiber fixed to the upper output alignment block. A generally-planar fiber guide is fixed transverse to the arm of a two-position switch. The guide includes an internal rectangular aperture for receiving the input fiber whose width and height each exceed the diameter of the fiber.

Abstract: An optical switch for selectively coupling the free end of an input fiber to the free ends of one of two output fibers. Each of the output fibers is adhesively fixed within a v-groove of an output alignment block. The output alignment blocks are held in stacked relationship within a housing with their v-grooves upturned. An input alignment block having an inverted v-groove within its bottom surface is provided for guiding the input optical fiber, upon switching, toward engagement with the output fiber fixed to the upper output alignment block.

Abstract: An optical switch (1) in accordance with the present invention includes: a housing (50), an input port (10), a plurality of output ports (11), an optical switching means (20), an indicating device (30) and a driving device (40). The optical switch includes a resistor (37), a fixed reflector (23) and a carrier (21) to which a moveable reflector (25) and a wiper contact (35) are mounted. The wiper contact slides on the surface of the resistor as the carrier moves along a pole (215), changing a resistance provided to a control circuitry. The control circuitry then provides control signals to turn on a light emitting component (31) above the output port which is optically connected with the input port.

Abstract: The invention provides a waveguide type liquid crystal optical switch that includes first and second cores so as to form a space therebetween, in which an optical path is switched between the first and second cores; a third core provided apart from the first and second cores, into which nematic liquid crystal orientated by an orientation film along a predetermined direction is filled, the third core overlapping to the space formed between the first and second cores; a first electrode arranged on an opposite side of the first and second cores with respect to the third core so as to overlap to the space between the first and second cores, second and third electrodes arranged on both sides of the first electrode, for orienting liquid crystal molecules along a direction perpendicular to the orientation direction of the orientation film; and a cladding for incorporating the cores and the electrodes.

Abstract: The present invention describes a method and devices for scaling the capability of a re-configurable add/drop multiplexer while not affecting the express traffic that goes through it. The invention allows field upgradability of re-configurable add/drop multiplexers with pre-selected wavelengths or wavebands such that other wavelengths or bands can be added or removed without service interruptions. This will then allow for a pay-as-you-grow model and therefore alleviate the need for having costly OADMs with a large number of addressable channels. In addition, in one of the embodiments we will describe a method for removing single point of failure through design, which is highly desirable from a network maintenance perspective.