Abstract: A 2×2 fiber-optic (FO) switch using electronically controlled light beam deflectors such as acousto-optic deflectors is described. The switch structure can be modified to serve as variable FO attenuators and frequency shifters. The basic no moving parts FO switch/attenuator structure can be used for routing and controlling multiple light signals in optical networks such as wavelength division multiplexed (WDM) optical communications, distributed sensor networks, and photonic signal processing systems requiring optical routing and gain control.

Abstract: An add/drop device is described that allows channels from a multi-channel optical path to be dropped to a device and a new or modified channel to be added to the multi-channel optical path. The device thereby has access to a channel from the multi-channel optical path without having access to all of the channels. In one embodiment, the add/drop device of the invention includes one or more intermediate ports and a switch. The intermediate ports communicate the channels not dropped by the add/drop device and the switch selectively optically couples the dropped channel either to the device or to be added back into the multi-channel path. The switch also selectively optically couples the new or modified channel to be added to the multi-channel path. The one or more intermediate ports allow multiple add/drop devices to be optically coupled together to provide a configurable add/drop mechanism.

Abstract: An optical switch for switching an optical path of an input optical signal comprises a substrate composed of a silica glass substrate, a separation layer formed on the silica glass substrate, a plurality of cantilever beams and formed in parallel to one another on the separation layer and connected at their tip ends to a connection member, at least one silica glass optical waveguide core formed on the cantilever beams, a plurality of optical waveguide fixed in opposition to the silica glass optical waveguide core, a cover for covering the cantilever beams, and a switch drive unit for bending the cantilever beams. The switch drive unit comprises electromagnetic actuators, which comprise soft magnetic bodies formed on the connection member for the cantilever beams and on the substrate, soft magnetic yokes formed of a soft magnetic body, permanent magnets, and wire coils.

Abstract: An optical transmission device which reduces optical noise in an optical transmission system. The optical transmission device includes a core light amplifying unit, and a first buffer light amplifying unit for amplifying a first signal light from a first transmission path and an amplified second signal light from the core light amplifying unit. The first buffer light amplifying unit supplies the core light amplifying unit with the first signal light, and supplies the first transmission path with the amplified second signal light. Also provided is a second buffer light amplifying unit for amplifying a second signal light from a second transmission path and an amplified first signal light from the core light amplifying unit. The second buffer light amplifying unit supplies the core light amplifying unit with the second signal light, and supplies the second transmission path with the amplified first signal light.

Abstract: Disclosed is an acousto-optic device having a number of acoustic attenuating structures and a method to limit the parasitic effects of a surface acoustic wave. The structures include any combination of the following: surrounding the acousto-optic conversion region with acoustic absorber, placing acoustic absorber near to the transducer(s), placing a strip of acoustic absorber between optical waveguides formed in the device, shaping one or more ends of acoustic waveguides formed in the device to absorb energy from the transducer(s), and/or extending the acoustic waveguides to further limit irradiation of unguided acoustic waves.

Abstract: The invention relates to a micro-optic switch used for transmitting optical signals between optical fibers. More particularly, the invention pertains to a micro-optic switch using polymer structures to position a microactuator and optical fibers on a substrate so that the microactuator can move an optical fiber cantilever between two fixed fibers to transmit optical signals between either one of the fixed fibers and the cantilever fiber. Using polymers instead of micromachined structures to position components of the switch reduces cost and simplifies assembly. The invention further provides processes for producing a micro-optic switch and for switching the path of an optical signal.

Abstract: A 2.times.2 optical fiber switch has a structure that does not produce an alignment error between the position of the central axis of optical fiber assemblies with lenses and the symmetry center position of rectangular prisms, thereby obviating the need of the skill for assembling adjustment. The 2.times.2 optical fiber switch is provided with first, second, third, and fourth optical fiber assemblies with lenses that are disposed such that the optical axes thereof are parallel in the same reference plane. The optical fiber assemblies with lenses are supported by a lens holding member. A prism holding member is supported by the lens holding member such that it supports first and second prisms and moves between a coupling position and a retreated position in a direction perpendicular to the reference plane.

Abstract: A non-blocking optical switch has a non-dilated architecture wherein dual mode input waveguides are connected to first and second inputs of mode selective couplers through mode conversion devices. Switching is effected by signals from a processing unit applied to a mode converter to convert the signal to be switched from a fundamental mode to a higher order mode. The mode selective coupler then couples the signal to one of the outputs thereof, whereas fundamental mode signals pass through to the other output thereof. An array of rows (layers) and columns of such elements make it possible to switch any incoming signal to be switched to any of a plurality of outputs after reconversion to the fundamental mode.

Abstract: An optical fiber switch for switching N.times.2N (N.gtoreq.1) circuits is capable of mechanically switching a plurality of pairs of optical fiber circuits at the same time. The optical fiber switch moves an N (N.gtoreq.1) number of movable optical fibers at the same time by a drive member which is guided by a slit of alignment members and reciprocated at right angles or in the X direction with respect to an optical axis. The optical axes of the movable optical fibers are accurately aligned with the optical axes of first or second fixed optical fibers by a mechanism which presses the N (N.gtoreq.1) number of the movable optical fibers against alignment V grooves at the same time by utilizing the flexure stress of an elastic pin provided on an actuator. Further, the elastic pin imparts a self-holding function to the actuator.

Abstract: One-by-three and two-by-two optical switches comprising optical waveguides or fibers with tapered ends that utilize electrostatically-driven actuators are disclosed. Tapering of the fiber ends allow the ends to be positioned in close proximity to one another to yield an optical switch with low insertion loss.

Abstract: An optical interconnection apparatus including waveguide arrays, such as grating routers and star couplers, has reduced coupling loss by reducing the width of the waveguides in the array, where they connect to the free-space region, so that they are smaller than the gaps between adjacent waveguides. The free-space region is formed by a slab whose thickness is tapered in a transition region, where it connects to the waveguide arrays, so as to essentially eliminate any mismatch loss that would otherwise be caused in an abrupt junction of the waveguide arrays with the free-space region.

Abstract: An end station of a both-way optical link comprises: a receiver (RX) preceded by a receive optical amplifier (RA); a transmitter (TX) followed by a transmit optical amplifier (TA); a pump laser diode (PX) for delivering the pumping waves required by said amplifiers; and a coupler (B) of the passive type having two groups of two branches. The two branches of one group (BL and BP) are connected respectively to a line fiber (L) for both-way light guidance and to the pump (PX), the two branches of the other group (BR and BT) being connected respectively to the receive optical amplifier (RA) and to the transmit optical amplifier (TA). An in-line optical amplifier apparatus can be constituted in similar manner. The invention is applicable to telecommunications.

Abstract: A scalable, non-blocking fiber optic matrix switch has two arrays of light beam collimators arranged to face one another in free space, and a number of optical fibers coupled to each of the arrays. Each collimator has a tubular body with a fiber receiving part at one end, and a lens mounting part at an opposite end of the body. A lens fixed in the mounting part produces a collimated light beam from light emitted from an end of an optical fiber inserted in the fiber receiving part. First and second motor assemblies with corresponding positioning elements displace the collimator body so that its light beam is steered to a desired position along "X" and "Y" axes in response to operation of the motor assemblies. A signal carried on a fiber entering a first collimator in one array can be switched into a fiber of a second collimator in the opposite array, by displacing the collimators so as to direct the beam of the first collimator to align with a lens axis of the second. For an N.times.

Abstract: An optical index switch including curved ridge waveguides. The cladding around the waveguides is selectively etched to produce tightly curved optical switches.

Abstract: A thermally activated silica optical circuit switch that uses light from a light source, such as a laser, to heat various regions of the switch to produce a switching function. In one embodiment, the switch includes silica glass formed on a substrate, such as a silicon substrate, and at least one input waveguide and one output waveguide formed within the silica glass. A light source is then used to generate light that illuminates a path in the silica glass that couples a particular input waveguide to a particular output waveguide. The light from the light source has a wavelength that enables it to be substantially absorbed by the silica glass and substantially transmitted through the substrate. The illumination by the light increases the temperature and correspondingly the index of refraction of the silica glass in the path. A light signal is then able to travel through the coupled waveguides via the increased index of refraction of the silica glass within the path.

Abstract: Methods and apparatus for performing optical signal switching or other optical routing functions in an optical device or system, in which crosstalk induced by modal interference is suppressed by providing appropriate loss, gain and/or refractive index changes in different parts of a switch structure. An exemplary optical signal switch includes first and second branches each having a refraction-controlled section and an absorption-controlled section. An optical signal path over which an optical signal propagates in passing through the switch is selected to include a portion of at least one of the first and second branches, such that one of the first and second branches is a selected branch and the other branch is a non-selected branch.

Abstract: A polarization beam splitter separates the optical data signal into first and second orthogonally polarized optical signals. A first variable time delay element provides a first incremental propagation delay for the first polarized optical signal. A second variable time delay element provides a second incremental propagation delay for the second polarized optical signal. The first and second variable time delay elements consist of a series of optical switches optically interconnected by different incremental lengths of optical fiber. For example, 2.times.2 optical switches are provided for switching between a reference fiber segment and a respective delay fiber segment to provide a relative incremental propagation delay. A controller controls optical switches in the first and second variable switching delay elements to set first and second incremental propagation delays.

Abstract: The method builds upon the highly repeatable properties of commercial optical fiber, and using commercial fiber for the waveguides in a fabric of optical switches. The method describes assembly of the fabric, locating the intersections, and a structure for placing the mating resistor.

Abstract: The present invention relates to an optical coupler 2.times.2 optical switch which can efficiently shorten the length of device by employing a cantilever and a movable optical waveguide and a method for optical switching with the optical coupler 2.times.2 optical switch. An optical coupler 2.times.2 optical switch of the present invention comprises: an optical coupler in which two fixed optical waveguides are provided on a substrate; an optical waveguide positioned between the fixed optical waveguides, which is moved up and down; and, a cantilever which is linked to the optical waveguide to move the optical waveguide up and down by the voltage applied to electrodes. Since the coupling length of the optical coupler(22) is changed depending on the distance between the fixed optical waveguides(21, 21') and the optical waveguide(23), length(D) of the optical, coupler(22) can be shortened to a great extent compared to the prior art optical coupler 2.times.

Abstract: A low profile optical switching device has a housing with a width and length considerably greater than its height, a motor having an upright shaft extending less than the height of the housing, a circular faceplate surrounding an upper end portion of the shaft and having a diameter considerably larger than the length of the shaft, and a plurality of first optical fibers each having a fixed fiber end portion held by the faceplate. The fixed fiber end portions, usually constituted by lenses, are arranged so as to define a substantially cylindrical imaginary surface co-axial with and communicating with the faceplate. These fixed fiber end portions can receive light from a further optical fiber having a movable end portion carried by an arm extending radially from the motor shaft and which moves around a circular path adjacent the fixed fiber end portions, the light being transmitted via a prism mounted on the arm adjacent the movable fiber end portion.

Abstract: An optical coupling device for a node in a self-healing optical network, wherein the number of switching elements is reduced by using a novel type of optical 2.times.2-switch. The switch has two switching states: (i) a bar state (ss1) in which a first and a second main port are optically coupled through to a first and a second secondary port, respectively; and (ii) a half-cross state (ss2) in which the main ports are coupled through to one another and in which the secondary ports are not involved in any through-coupling. An integrated design of the switch is based on two asymmetric Y-junctions coupled to one another via a common side branch in which electrodes are active in order to vary the propagation constant. Accordingly, a compact, integrated version of the optical coupling device with only two switching elements can be achieved.

Abstract: An optical filter, such as a wavelength-division multiplexer, demultiplexer, or optical router, in which several single-mode waveguides are coupled to the sides of an optical interaction region containing a wavelength dispersive element that collects light from one or more input waveguides inputting light to the interaction region and disperses it according to wavelength to one or more output waveguides outputting wavelength-separated light. According to the invention, a multi-moded waveguide is interposed between one or more of the single-moded waveguides and the optical interaction region. It has a predetermined length to create at one end a multiply peaked image of a singly peaked profile presented to it at the other end, thus being a multi-mode interference (MMI) filter that presents a flatter filter profile at the interface between the MMI and the optical interaction region and affords reduced filter sensitivity to wavelength drift of an optical signal.

Abstract: A wavelength selective acousto-optical waveguide device comprises a first and a second optical path in an optical waveguide having a length different by an amount corresponding to a value d=.+-..lambda.(k +m) where d is the difference between the optical paths of the two waveguides, .lambda. is the wavelength of the optical signal, k is a number greater than 0 and less than 1; and m is 0 or a whole number, so as to create a phase shift between at least two parasitic components of the optical signal, such as to generate a destructive interference between the parasitic components.

Abstract: A compact monolithic interferometric switch such as a Mach-Zehnder switch is formed such that one of the waveguide paths between the input and output couplers contains a material having exhibits a resonant nonlinearity, whereby its refractive index changes when pump power propagates through it. Each of the waveguide paths has a different propagation constant whereby signal light is subjected to a different delay in each path when no pump power is propagating through the rare nonlinear path. An input signal applied to the input of the switch appears at a first output terminal when the pump power does not propagate through the nonlinear path, and it appears at a second output terminal when the pump power is applied to the nonlinear path. Switching occurs at relatively low levels of pump power.

Abstract: An integrated optical circuit is described for coupling an optical fiber amplifier with two or four terminals in such a way that the optical fiber amplifier is supplied with optical signals in a prescribed direction, and the optical signals are coupled out to an optical network via a directed directional coupler. The necessary optical switches, couplers, terminals and light guides are integrated into the integrated optical circuit.

Abstract: A method and apparatus for aligning optical fibers to light input and output ports or ends of a semiconductor waveguide device includes forming an LED diode in the associated substrate proximate each associated port. Each LED is positioned emitting light from the primary output mode position of its associated port. During alignment of an optical fiber to a given port, one end of the fiber is adjustably positioned adjacent the light output/input area at the given port in close contact thereto, and the other end of the optical fiber is connected to an input of an optical power meter the associated LED is energized, and the one end of the optical fiber is adjusted in position to maximize the light output intensity or power detected by the meter.

Abstract: An optical switch wherein mirrors move between two positions in order to transmit optical signals between input fibers and output fibers. In a first position, the optical signal is transmitted by input fibers through a one-quarter pitch of Grade Index Refractive (GRIN) lens. The light signal is then reflected by a first mirror and second mirror such that its path carries it to a focusing one-quarter GRIN lens, and to output fibers. With the mirrors in its second position, the optical signal is transmitted directly from input fibers, through one-quarter pitch of Grade Index Refractive (GRIN) lens, to a focusing one-quarter GRIN lens, and to output fibers, thereby resulting in an unreflected light signal path.

Abstract: An optical switch includes a dual-core optical fibre coupler having waveguides which are erbium doped, silica-based fibre amplifiers. The waveguides are pumped by pump lasers which are used to control the mean differential gain of the waveguides to be zero or a first value at which two values the linear coupler is a cross-coupler or a through-coupler at an operating wavelength.

Abstract: Disclosed is an optical switch device for totally reflecting an incident light therein in accordance with a change in refractive index occurring owing to current application, which is manufactured by the steps of: sequentially forming an optical waveguide layer, an n-InP clad layer and an n-InGaAs cap layer on a main surface of an n-InP substrate using an epitaxial growing; selectively etching the n-InGaAs cap layer to form an opening tapered downward; diffusing an impurity into the n-InP clad layer through the opening and into the n-InGaAs cap layer to a predetermined depth from a surface thereof so as to form a first impurity diffused region in the n-InP clad layer under the opening and to form a second impurity diffused region along the surface of the n-InGaAs cap layer; etching the layers on the optical waveguide layer using a mask to form a ridge-shaped waveguide; and forming electrodes on the n-InGaAs cap layer and an exposed surface of the n-InP clad layer and on a surface which is opposite to the main

Abstract: A ganged optical switch is provided for switching a first optical fiber into and out of axial alignment with a second optical fiber. The fibers are secured to first and second carriages respectively. By relatively moving the carriages, the optical fibers can be moved into and out of axial alignment. Two test optical fibers ganged to the first and second optical fibers provide test path for transmitting an optical signal along. The fibers forming the test path are positioned at particular locations on the carriages such that when the test optical fibers are axially aligned, the first and second fibers are guaranteed to be axially aligned. An optical detector is positioned at an end of one of the test fibers and an LED is provided at an end of the other of the test fiber. An indication of alignment is provided when light from the LED is detected by the optical detector.

Abstract: The device includes a first and a second optical circulator (C1, C2) having an input port and an output port that are the inputs and the outputs of the switch, as well as an optical bandpass filter (FP) placed between the two circulators (C1, C2) and connected with means for switching its state so that the filter either reflects or transmits a given wavelength, thus allowing a carrier with this wavelength at the input port of one of the circulators (C1, C2) to reach the output port of the same circulator or the output port of the other circulator.

Abstract: An optical switch wherein mirrors move between two positions in order to transmit optical signals between input fibers and output fibers. In a first position, the optical signal is transmitted by input fibers through a one-quarter pitch of Grade Index Refractive (GRIN) lens. The light signal is then reflected by a first mirror and second mirror such that its path carries it to a focusing one-quarter GRIN lens, and to output fibers. With the mirrors in its second position, the optical signal is transmitted directly from input fibers, through one-quarter pitch of Grade Index Refractive (GRIN) lens, to a focusing one-quarter GRIN lens, and to output fibers, thereby resulting in an unreflected light signal path.

Abstract: A vehicle lighting system includes one or more central light sources, a plurality of optical loads including headlight lenses, an optical fiber network that extends from the light sources to illuminate the headlight lenses and other optical loads, and optical switches and oscillators that include respective input fibers illuminated from the light source and output fibers to respective optical loads, and operate by enabling and disabling optical connections between their input and output fibers. The headlight assemblies switch between high and low beams by moving their fibers vertically, and control beam diffusion by moving the fibers parallel to the lens axes, including an automatic diffusion adjustment for a headlight reflection from a vehicle in front.

Abstract: A first pair of optical fibers are held and fixed to a supporting member in a cantilever form, and oppositely connected to a second pair of the optical fibers that are fixed to a square hole of the alignment material. A magnetic body is adhered to each of the first pair of optical fibers. Around the magnetic bodies, there are aligned hollow solenoid coils, and one pair or two pairs of permanent magnets respectively are oppositely aligned so as to have opposite polarities to each other.

Abstract: An optical switch comprises a substrate, a first thin film layer formed on the substrate and including a first optical waveguide having a coupling portion and tapered portions therein, a clad layer formed on the thin film layer, a second thin film layer formed on the clad layer and including a second optical waveguide having a coupling portion and tapered portions, wherein a compound including a photochromic material is contained in the clad layer.

Abstract: A Fabry-Perot etalon 10 is located in the light path 30 between a light sourcesinks 40 and 44. The etalon is polarization insensitive, and its optical path length and transmission wavelength(s) is controlled by a bias source 60. When light at the desired wavelength is propagating from source 40, the bias is set to establish transmission through the etalon at that wavelength, whereupon the light propagates to the sink 44, and the switch is transmissive. By contrast, if the switch is to be nontransmissive, the bias sets the transmission wavelengths of the etalon on either side of the wavelength produced by source 40, whereupon the light from source 40 is reflected by the etalon, and does not reach sink 44. In a second embodiment, a third sourcesink 48 is coupled in a second light path 330a, for being coupled to the first sourcesink 40 when the etalon is set for reflection, to thereby form a single-pole, double-throw switch.

Abstract: A three or more section reverse .DELTA..beta. directional coupler designed to operate at a number of coupling lengths (L/l) selected from a region of a corresponding switching diagram where the cross and bar state switching curves are approximately parallel to each other and to the vertical axis, the vertical axis defining numbers of coupling lengths, or from a region of corresponding process sensitivity plots for the cross and bar states where the cross and bar state voltage curves are both approximately of zero slope. A number of these directional couplers form an optical switching array and a number of arrays form a system or network for switching optical signals each of which are capable of operation with uniform cross and bar state voltages at low crosstalk levels.

Abstract: In a total internal reflection-type optical waveguide switch which comprises optical waveguides crossing each other so that a refractive index changing region for developing a reflective surface is formed at a crossing section between the waveguides, the refractive index changing region has a configuration such that the reflective surface constitutes a concave surface recessed with respect to one lateral portion of the crossing section. When the refractive index changing region is not activated, incident light upon the spot corresponding to the reflective surface is insensitive to changes of the refractive index in the refractive index changing region, so that the initial crosstalk level can be lowered.

Abstract: Operating point trimming methods for an optical waveguide modulator and an optical waveguide switch are disclosed. One operating point trimming method for an optical waveguide modulator comprises, for example, the step of removing, while monitoring the waveform of an intensity modulated light beam, a portion of either one of a first and a second electrode such that the intensity modulated waveform takes on a desired waveform. One operating point trimming method for an optical waveguide switch comprises the step of removing a portion of either one of a first and a second electrode while monitoring output light beams.

Abstract: A 1-input/2-output or 2-input/2-output directional coupler type optical device comprising a junction including two optical waveguides arranged parallel to each other and each fitted with an electrode for controlling a propagation constant, the incidence end or ends of one or both of the optical waveguides being connected to curved or straight optical waveguides, thus forming an incidence-side lead section, and the respective emergence ends of the two optical waveguides being optically connected to curved or straight optical waveguides, thus forming an emergence-side lead section. An electrode for suppressing the mode coupling is mounted on each optical waveguide of the emergence- or incidence-side lead section. A high extinction ratio of 30 dB or more can be obtained in either of cross and through modes by activating a required one of the mode coupling suppressing electrodes while applying an electrical signal to each propagation constant control electrode.

Abstract: A structure for optically coupling at least one optical conductor to an optical input or output of an optical device includes a carrier, having the optical conductor embedded therein such that the optical conductor has at least one locally bent portion reaching an outer surface of the carrier and forming there at least one optical contact point to which the optical input or output of the device may be coupled. Conductor positioning structure is provided disposed in the carrier, for accurately positioning the conductor in the carrier. Cooperating positioning structure, disposed on the carrier at the surface reached by the bent portion of the conductor, co-operates with corresponding complimentary positioning structure of the optical device.

Abstract: A 2-input/2-output directional coupler is arranged as an element coupler/splitter for a first stage, and 1-input/2-output coupler/splitters are used as element coupler/splitters for a second stage and subsequent stages. Output ports of these element coupler/splitters are concatenated with input ports of other element coupler/splitters to form a 2-input/multi-output coupler/splitter. An optical signal can be inputted through one input port of the first-stage 2-input/2-output directional coupler, and an optical signal for optical line monitoring can be inputted through the other input port. It is unnecessary, therefore, to use an optical wavelength division multiplexer/demultiplexer or other optical part which conventionally is connected at the time of optical line monitoring.

Abstract: Disclosed is an optical switching connector including a ferrule plate, which fixes an end of an optical fiber to a predetermined position, has pin grooves formed in parallel at its both ends, and has at least one of its pin grooves formed to a width enabling horizontal movement of a reference pin, pin holding members which position the reference pin in said pin grooves, and a frame body which houses said ferrule plate and pin holding members. The optical switching connector is characterized in that the pin holding members are provided individually for each pin groove and provision is made at the both sides of the pin grooves of members for pressing the pin holding members corresponding to the pin grooves where the reference pins can move horizontally to the ferrule plate.

Abstract: An optical switch includes at least one input optical semi-conductor waveguide. Two output optical semiconductor waveguides are connected at a branch point to the input optical waveguide, and diverge from the branch point with a preset angle .theta. (degree) between them. A refractive index controlling portion is located on at least one of the output optical waveguides and away from the branch point. The refractive index controlling portion effects a light mode cut-off by electromagnetically causing a reduction of the refractive index of the associated output optical waveguide.

Abstract: A waveguide type optical circuit element having a directional coupler for converting light intensity between two waveguides, which is used as a polarity-independent optical switch or a variable optical divider for optical fiber communications and the like. The two waveguides (2), (3) have a coupling section length which is in a TE mode about three times a complete coupling length of the TE mode, and in a TM mode about one time a complete coupling length of the TM mode. Electrodes (4), (5) comprise three-part electrodes of different lengths which act as reverse .DELTA..beta. electrodes for alternately reversing a direction of an electric field. This construction promotes the light-confinement effect of the waveguides, reduces the drive voltage necessary for carrying out an optical switching operation, and realizes optimal element characteristics in accordance with a ratio of variations in the propagation coefficient in the TE mode and TM mode of the directional coupler manufactured.