Abstract: A planar lightwave circuit comprises a waveguide that is thermally-compensating. The waveguide comprises a cladding and a core that comprises two regions running lengthwise through the core. One region has a negative thermo-optic coefficient; the other region has a positive thermo-optic coefficient.

Abstract: The present invention provides a silicon wave-guide (3), with a silicon oxide cladding (2, 4) on a silicon substrate (1). At predetermined positions along the length of the wave-guide, are created metal oxide semiconductor (MOS) structures. A poly-silicon, or any other conductive layer (5), is deposited and patterned above the upper cladding (4) and electrical contacts are made to the substrate (1), the silicon wave-guide (3), and the poly-silicon layer (5). Upon the application of a potential difference between at least two of the layers from the group comprising the substrate (1), the silicon wave-guide (3), and the poly-silicon layer (5), the free carrier concentration at the top and/or bottom layer of the silicon wave-guide (3) is changed by the electric field. The change in the electric field results in a change in the index of refraction, and the change in the index of refraction causes a change in the optical mode propagating in the waveguide (3).

Abstract: A method of in-wafer testing is provided for a monolithic photonic integrated circuit (PIC) formed in a semiconductor wafer where each such in-wafer circuit comprises two or more integrated electro-optic components, one of each in tandem forming a signal channel in the circuit. The method includes the provision of a first integrated photodetector at a rear end of each signal channel and a second integrated photodetector at forward end of each signal channel. Then, the testing is accomplished, first, by sequentially operating a first of a selected channel electro-optic component in a selected circuit to monitor light output from a channel via its first corresponding channel photodetector and adjusting its operating characteristics by detecting that channel electro-optic component output via its second corresponding channel photodetector to provide first calibration data.

Abstract: A first film (8) is formed between a substrate (1) and a signal electrode (3); ground electrodes (5) and (6) which constitute an optical waveguide device (10), and a second film (9) is formed between the substrate (1) and a signal electrode (4); ground electrodes (6) and (7). An optical phase modulator (10A) is composed of the substrate (1), an optical waveguide (2), the signal electrode (3), the ground electrodes (5) and (6), and the first film (8). An optical intensity modulator (10B) is composed of the substrate (1), the optical waveguide (2), the signal electrode (4), the ground electrodes (6) and (7), and the second film (9). The optical waveguide device (10) is composed of the optical phase modulator (10A) and the optical intensity modulator (10B), which are integrated monolithically.

Abstract: Optical modulators with reduced temperature dependence on bias control are described. A set of bias electrodes is arranged relative to a set of RF electrodes in a manner which results in the opening point of the device remaining relatively constant as a function of temperature. The arrangement of the bias electrodes relative to the RF electrodes includes a physical offset of one set of electrodes relative to the other, with or without a reversal of polarity of one set of electrodes relative to the other. Arrangements according to the present invention create a symmetrical electrode arrangement from a temperature-induced stress point of view so that the operating point of the device remains relatively constant as a function of temperature.

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: The invention relates to a method and a device for controlling the refractive index in the core of an optical fiber. According to the invention, an optical fiber is provided with a longitudinal electrode running along the core of the fiber. An electric current is passed through the electrode to induce ohmic heating thereof, causing thermal expansion and consequently a compressing force upon the core of the fiber. This compression of the core leads to induced changes in the refractive index in the direction of the compressing force, and hence induces or alters birefringence in the core.

Abstract: The attenuation from connectors to the interaction region of the light signal with the microwave can be reduced, and the bandwidth can be improved in an optical waveguide device, in which a space between strip lines on a ceramic substrate at one end of the strip lines connected to first and second input sections is adapted to be narrower than a space between the strip lines at the other end of the strip lines connected to first and second electric connectors.

Abstract: There is provided a high performance optical waveguide type optical modulator with excellent long term reliability, in which contamination of the buffer layer in a forming process of a signal field adjustment region on the buffer layer by a lift-off method or an etching method, is prevented and DC drift thus suppressed.

Abstract: An optical waveguide device 1A has a substrate 22 and a supporting body 10 for supporting the substrate. The substrate 22 has a main body 2 made of an electrooptic material and one and the other main faces, optical waveguides 3a, 3b and electrodes 4B, 4C provided on the side of the one main face 2a of the main body 2 The supporting body 10 is joined with the substrate 2 on the side of the other main face, and the electrode has a feedthrough portion. The device 1A further has a low dielectric portion 7 provided under the feed through portion and between the other main face 2b of the main body 2 and the supporting body 10.

Abstract: A tunable Bragg grating method and apparatus. In one aspect of the present invention, a method according to an embodiment of the present invention includes directing an optical beam into a first end of an optical path having the first end and a second end disposed in a semiconductor substrate, reflecting a first portion of the optical beam having a first center wavelength back out from the first end of the optical path and tuning the optical path to reflect a second portion of the optical beam having a second center wavelength back out from the first end of the optical path. In one embodiment, the Bragg grating is tuned with a heater used to adjust a temperature of the semiconductor substrate. In another embodiment, charge in charge modulated regions along the optical path is modulated to tune the Bragg grating.

Abstract: The optical deflector comprises: an optical waveguide 12 of a dielectric material having electrooptical effect; and a pair of electrodes 10, 14 opposed to each other across the optical waveguide, an electric field is applied between the opposed electrodes to change a refractive index of the dielectric material to thereby control a propagating direction of signal light propagating in the optical waveguide 12, wherein the dielectric material has a first refractive index in its initial state, has a second refractive index by application of an electric field of a first polarity, and retains as a third refractive index a refractive index obtained after the electric field has been removed. The dielectric material has the third refractive index has the first refractive index by the application of an electric field of a second polarity different from the first polarity and removal of the electric field.

Abstract: The invented modulator provides ultra-high linearity (SFDR=147 dB-Hz), high tolerance, low loss, simple architecture, and low cost. It is based on unique combination of phase-modulator (PM) and ring resonator (RR) that are coupled to the arm(s) of standard Mach-Zehnder interferometer (MZI) configuration. It comprises of input port to receive optical signal 1, optical power separating means 2, interferometer arm length paths 3 & 4, bias controller mean 5, PM 6, RR 7 with coupler 17 having coefficient ?, optical power combining means 8, RF power splitting means 9, RF power source 10, and optical output signal 15. Both PM 6 and RR 7 are driven by same RF source 10 whose output power is divided into two parts with a split ratio of F:(1-F). The role of RR 7 is to provide the necessary non-linear phase-correction. It operates under non-resonance condition to avoid bandwidth narrowing. The dual modulation of PM 6 and RR 7 is an important factor in this invention.

Abstract: A method of, and apparatus for, setting an operating (control) voltage of a voltage controllable optical component, such as a Mach-Zehnder optical modulator, having a periodic voltage/optical parameter (optical power) characteristic include an up/down counter and a digital to analog converter operable to set the voltage applied to the component to a predetermined initial value, a device for measuring the optical parameter, and another device for sequentially progressively increasing and decreasing the voltage (incrementing/decrementing the counter) with respect to the predetermined value, and for determining respective voltage values which produce maximum and minimum values of the optical parameter. The voltage is set to a value intermediate the maximum and minimum voltage values. Further, the apparatus determines the sense of the slope of that portion of the periodic characteristic lying between the maximum and minimum values for use by a control loop during subsequent operation of the optical component.

Abstract: A waveguide device is provided comprising an optical waveguide core and a cladding optically coupled to the optical waveguide core. The cladding comprises an optically functional region defining a refractive index that is configured to vary in response to a control signal applied to the optically functional region. The refractive index of the optically functional region is lower than the refractive index of the optical waveguide core. In accordance with one embodiment of the present invention, the optically functional region may be characterized as a Kerr Effect medium.

Abstract: The invention provides an optical switch that consumes a less power, excels in a high-speed response, and possesses a structure suitable for a miniaturization and multi-channel switching. The optical switch switches a plurality of input signals to a plurality of output positions, in which a laminated structure that has a nonlinear optical layer and a buffer layer laminated in the same number as that of input parts intersects an optical path between the input parts and output parts. By providing the laminated structure using the nonlinear optical thin films, the invention achieves a small matrix optical switch excellent in a high-speed response and suitable for switching a large-capacity of information.

Abstract: An optical modulator includes a p- or n-type semiconductor layer that is provided at an upper part of an optical waveguide path, and modulating electrodes that are provided at intervals on the semiconductor layer in an extension area of the optical waveguide path. The semiconductor layer has first regions located immediately under the modulating electrodes, and second regions located between the first regions. The second regions have separators that electrically separate the first regions from one another.

Abstract: By a method for controlling the state of polarization (SOP) of an optical signal transmitted through an optical waveguide, the waveguide is buried in a planar structure and a plurality of stress-applying films, having variable stress, are placed on the top of the structure. Preferably the stress-applying films comprise materials that have thermal expansion coefficients different from that of the planar structure or comprise materials with piezoelectric properties. In this way it is possible to produce a cascaded series of optical elements with variable linear birefringence in a planar optical waveguide. Moreover according to the invention it is possible, by the method according to the invention, to manufacture optical components having an active polarisation controller.

Abstract: An optical switch includes a polarization splitter/combiner that is made of a material that changes its refractive index in response to voltage. The polarization splitter divides an input beam into a first polarized component and a second polarized component. Each of the first and second polarized components is fed into a first polarization-sensitive deflector and a second polarization-sensitive deflector, each of which deflects a light beam by a predetermined angle. A plurality of polarization combining systems are positioned to receive a deflected first component and a deflected second component and combine the first and the second deflected components into an output beam propagating through an output fiber.

Abstract: A resonant optical modulator includes an electro-optical substrate, an optical waveguide formed in the substrate and having a variable index of refraction, and an active modulator electrode formed on the substrate in relation to the waveguide to effect electro-optical variation of the index of refraction upon application to the electrode of a modulating signal. An interface port formed on the substrate provides the modulating signal to the electrode from a signal source and has an impedance. An electrical structure, formed on the substrate and coupled to the interface port and the electrode, makes an impedance of the optical modulator substantially equal to the impedance of the signal source. The electrical structure includes a delay line and a stub formed on the substrate.

Abstract: A power balanced photonic RF phase shifter includes: a microwave drive; a phase controller operably connected to the microwave drive; and a linearizing arm connected in parallel with the microwave drive, the linearizing arm operating under a bias voltage, Vlin, that is controlled such that power variations of the photonic RF phase shifter are mitigated. In a preferred embodiment, the bias voltage, Vlin, is controlled to keep an optical phase of the photonic RF phase shifter at a constant value. In a preferred embodiment, the microwave drive, the phase controller and the linearizing arm comprise (three) Mach-Zehnder modulators.

Abstract: An optical waveguide for guided an incident light is formed on a substrate having an electro-optic effect. A first buffer layer is formed to cover an upper surface of the substrate. A conductive film is formed above the first buffer layer. A center electrode and a ground electrode are formed for applying a voltage in order to induce an electric field in the optical waveguide. A second buffer layer is formed between the conductive film and at least one of the center electrode and the ground electrode. The conductive film is formed to be present on at least a part below the ground electrode. A light guided through the optical waveguide is modulated by changing a phase by a voltage applied to the optical waveguide. Thereby, a thermal drift can be effectively restricted so that an optical modulation device having excellent electric characteristics can be realized.

Abstract: A microchip may include an optical signal routing system. The optical routing system may include a distribution waveguide coupled to a light source and signaling waveguides interconnecting source and destination locations. A directional coupler may be used to couple and modulate light from the distribution waveguide to a signaling waveguide at a source location. A photodetector may be used to convert light signals from the source location into electrical signals at the destination.

Abstract: The invention relates to suppression of high frequency resonance in an electro-optical device. The electro-optical device includes an optical waveguide formed in a substrate and a plurality of electrically floating electrode segments that are positioned on the substrate to intensify an electric field in the optical waveguide. The device also includes a RF ground electrode that is positioned on the substrate. The RF ground electrode defines a slot having a shape that suppresses modal conversion and propagation of high order modes in the RF ground electrode and in the plurality of electrically floating electrode segments, thereby suppressing modal coupling to the substrate. The device further includes a buffer layer formed on the upper surface of the substrate, on the plurality of electrically floating electrode segments, and in the slot. A driving electrode receives a RF signal that induces-the electric field in the optical waveguide.

Abstract: An electro-optical deflector device, having a thin ferroelectric oxide film and a method of fabricating the deflector device is described. On embodiment of a thin film electro-optic deflector device includes: a planar optical waveguide, having a thin ferroelectric oxide layer; a first electrode, having a conductive substrate and a conductive epoxy; a second electrode coupled to the planar optical waveguide; a supporting substrate; a cladding layer attached to the second electrode deposited on the supporting substrate; and a hole through the supporting substrate and the cladding layer for connecting the second electrode to an external voltage source.

Abstract: A small-sized and low-cost silicon platform for optical modules which enables high-speed transmission. A conductor pattern is formed on an oxide layer formed on the surface of a silicon substrate through a dielectric film. A hole extending from the surface of the dielectric film to the oxide layer is formed in the dielectric film at a position for the formation of a bonding pad. A conductor material is directly formed on the oxide layer exposed to the bottom of this hole. This conductor material constitutes a bonding pad portion electrically connected to the conductor pattern.

Abstract: An optical deflector including an optical waveguide of a dielectric material having electrooptical effect; and a pair of electrodes opposed to each other across the optical waveguide. An electric field is applied between the opposed electrodes to change a refractive index of the dielectric material to thereby control a propagating direction of signal light propagating in the optical waveguide, wherein the dielectric material has a first refractive index in its initial state, has a second refractive index by application of an electric field of a first polarity, and retains as a third refractive index a refractive index obtained after the electric field has been removed. The dielectric material having the third refractive index has the first refractive index by the application of an electric field of a second polarity different from the first polarity and removal of the electric field.

Abstract: A device for optical space switching in optical networks. The optical device comprises a broad area optical waveguide section having a number of electrodes extending over at least a portion of the length of the broad area optical waveguide section. The application of an electrical signal to an electrode causes a local change in effective refractive index of the broad area optical waveguide section, thereby causing light preferentially to propagate along a predetermined path in dependence on the configuration of the electrode. In particular the broad area waveguide device is implemented in indium phosphide (InP). Also described is a method for waveguiding in the optical device.

Abstract: An optical waveguide device wherein a substrate is fabricated from a lithium niobate (LiNbO3) substrate; at least one optical waveguide is formed in the lithium niobate substrate in such a manner that two Mach-Zehnder type directional couplers are formed, and further a phase shifter is formed in between these directional couplers; and the phase shifter is provided with an electrode of a structure including a first thin film layer being an ITO thin film containing an oxide and a second thin film layer being a chromium thin film an oxide of which is acidic, whereby an electric field produced in response to a voltage applied to the electrode is given to the optical waveguide to function as a variable optical attenuator.

Abstract: An optical waveguide comprising an MgO substrate 10, and a slab waveguide layer 24 formed on the MgO substrate 10 and including a core layer 18 of a ferroelectric or an antiferroelectric, further comprises a stress alleviating layer 12 which substantially lattice-matches with the MgO substrate and the slab waveguide layer 24 and has an average thermal expansion coefficient in the range of 7.0×10?6-14.0×10?6/° C. at the room temperature to 700° C. Accordingly, the optical waveguide device utilizing the magnesium oxide substrate can be formed without breaking the optical waveguide layer and the magnesium oxide substrate itself.

Abstract: A method and system are disclosed for switching at least part of a light signal out of a first waveguide by a Bragg grating formed from an electro-optic effect in the first waveguide. The Bragg grating is created by turning on a series of electrodes on each side of the first waveguide. The electrodes create electric fields in the core of the first waveguide which raise the refractive index in certain regions of the core. When the electric fields are tilted and evenly spaced apart, at least part of a light signal propagating through the waveguide, at a predetermined wavelength, is reflected out of the first waveguide. The reflected light signal can be switched back into a second waveguide by use of another Bragg grating. When the electric fields are off in the first waveguide the light signal, including the part of the light signal having the predetermined wavelength, continues straight on through the Bragg grating area.

Abstract: A polarization transformer/PMD compensator chip contains a differential TE-TM phase modulator at its input. The modulator generates a TE-TM phase modulation. The mode converter voltages are driven with driving signals that are free of DC components. DC drift is thereby safely avoided.

Abstract: A tunable optical device for adding or dropping one or more channels in a wavelength division multiplexing communication system is disclosed. The tunable optical device comprises one or more filters, wherein at least one filter comprises (a) one or more elastimers and (b) one or more gratings. An elastimer is a polymer that expands and contracts with a change in a voltage applied across the polymer or when a certain wavelength of light is diffracted from or transmitted through the polymer.

Abstract: An apparatus/method for producing fabric-like electronic circuit patterns created by methodically joining electronic elements using textile fabrication-like methods in a predetermined arrangement.

Abstract: A process for fabricating an electro-optic device is decribed that includes: a) providing a substrate comprising at least two polymer micro-ridges, where each polymer micro-ridge comprises an upper surface and two walls, and the two walls form an angle with a lower surface; b) depositing a metal thin film on the upper surface, the two walls, and the lower surface; c) etching a predetermined amount of the deposited metal thin film on the lower surface, thereby forming two electrodes separated by a gap; d) depositing a nonlinear optical polymer in the gap between the two electrodes; and e) poling the nonlinear optical polymer to induce electro-optic activity.

Abstract: The present disclosure relates to a device for modulating light emitted by a laser, including an optical substrate that has an electro-optical effect, at least one optical waveguide formed near a front face of the optical substrate, a first electrode that is formed with a conductive transparent film so that a part of the optical waveguide may be covered and is used for applying an electric field to the optical waveguide, a second electrode that is paired with the first electrode and is used for applying an electric field to the optical waveguide, and a third electrode that is formed with a metal film in a position that is shifted from a position just above the optical waveguide and is electrically connected with the first electrode.

Abstract: A co-planar waveguide interferometric electro-optic modulator is disclosed. A Z-cut lithium niobate electro-optic substrate includes a first and second waveguide that are formed in the lithium niobate electro-optic substrate. An elongate RF electrode at least partially covers one of the waveguides. A slotted electrode is disclosed formed by two elongate substantially-parallel electrodes one of which is at least partially covers the other of the waveguides. At least one electrode is substantially greater, preferably at least twice the width of the elongate RF electrode.

Abstract: Optoelectronic and photonic devices are formed by employing polymer materials that have a lower glass transition temperature (Tg) than the nominal operating temperature. By using such materials, the local or segmental mobility is increased so that local stress is eliminated or minimized on the polymer material, making performance more robust. The current invention involves use of a polymer in an optical device in an operating temperature range in the region above Tg, where the polymer segments between crosslinks are allowed local freedom of movement; however, large-scale movement of the material may be restricted by the crosslinked structure of the polymer material.

Abstract: A method of attaching electrodes to optical substrates with embedded waveguides includes applying the electrode pattern to a separate superstrate from the electro-optic material containing the waveguide. This allows for the change of the index of refraction and/or the dipole moment of an electro-optic material using low voltages. In0 addition, the electrode superstrate can be detached from the waveguide substrate and repositioned and aligned to different waveguides. Removable electrodes add flexibility and increase yield by allowing the electrodes to be re-aligned to the waveguides when improper alignment occurs.

Abstract: A solid state optical interconnect system selectively interconnects a plurality of electromagnetic signals between a plurality of inputs and a plurality of outputs. The system includes a plurality of solid state, selectively actuatable 2×2 optical switching elements; and a plurality of all-optical signal paths extending through said 2×2 optical switching elements between the inputs and outputs. Each of said plurality of all-optical signal paths has substantially the same pathlength. This switch element is relatively robust and insensitive to environmental disturbances and has a reconfiguration time which is an order of magnitude faster than conventional opto-mechanical switches which generally require tens of milliseconds before reconfiguration. The switch element provides constant data pathlength for constant latency, loss, and unskewed data output.

Abstract: Optical modulators with reduced temperature dependence on bias control are described. A set of bias electrodes is arranged relative to a set of RF electrodes in a manner which results in the operating point of the device remaining relatively constant as a function of temperature. The arrangement of the bias electrodes relative to the RF electrodes includes a physical offset of one set of electrodes relative to the other, with or without a reversal of polarity of one set of electrodes relative to the other. Arrangements according to the present invention create a symmetrical electrode arrangement from a temperature-induced stress point of view so that the operating point of the device remains relatively constant as a function of temperature.

Abstract: The invention provides an electrooptic device and an electronic apparatus, in which the electrical characteristics of many thin-film switching elements formed in a substrate to support an electrooptic material can be accurately inspected. The invention also provides a method for making the electrooptic device. In a TFT array substrate of a liquid crystal device, an inspection TFT is formed in one of dummy pixels disposed at the periphery of a pixel region. A pixel electrode connected to a drain region of the TFT functions as a first inspection pad. In an adjacent dummy pixel, the pixel electrode electrically connected to an extended portion of a data line functions as a second inspection pad. In another adjacent dummy pixel, the pixel electrode electrically connected to an extended portion of a scan line via a junction electrode functions as a third inspection pad.

Abstract: An optoelectronic component has at least one monolithically integrated laser diode and at least one monolithically integrated optical waveguide. At least one of the optical waveguides is functionally coupled to at least two electro-absorption modulators, and at least one electro-absorption modulator is assigned at least one optical amplifier. The assembly forms an active electro-optical device that can be driven efficiently.

Abstract: In order to obtain an optical transmitter module for converting an input electric signal to a light signal with fidelity and outputting it therefrom, a terminal resistor Rt and an optical modulator MD are connected in parallel within a package including a laser diode with a monolithically integrated optical modulator for obtaining the light signal according to the electric signal. One thereof is grounded and the other thereof is connected to a wire inductance (L1) and an impedance matching resistor Rd in series with this parallel connection. Further, a high frequency transmission line (micro-strip line) MSL for the transmission of the electric signal is connected to the other end of the impedance matching resistor Rd.

Abstract: An optical waveguide device has an optical waveguide substrate and a supporting substrate. The optical waveguide substrate has a main body made of an electro-optic material and having a first main face and a second main face, an optical waveguide formed in or on the main body and an electrode formed on the side of the first main face of the main body. The supporting substrate is joined with the second main face of the main body. A low dielectric portion with a dielectric constant lower than that of the electro-optic material is formed in the supporting substrate.

Abstract: A data communication system comprising a plurality of fiber optic cables and a fiber optic switching system, comprising: a support structure for securing light emitting/light receiving ends of the plurality of fiber optic cables in predetermined positions; and, means for re-directing light emitted from the light emitting/light receiving end of one of the fiber optic cables to the light emitting/light receiving ends of one, or more than one, of a plurality of the plurality of fiber optic cables. The re-directing means includes means for collimating and directing the light emitted from the end of one of the cables as a beam propagating along a predetermined direction and for re-directing the beam towards the end of another one of the cables selectively in accordance with an electrical signal. More particularly, the re-directing means includes electro-optical phase shifting medium, preferably liquid crystal molecules.

Abstract: The invention relates to a method and a modulator circuit for modulating light in a modulator circuit. The modulator circuit comprises a Mach-Zehnder modulator having at least one optical input and at least one optical output, said Mach-Zehnder modulator modulating light, which is fed to the input of the Mach-Zehnder modulator in response to applied electrical modulation signals from a driver circuit. According to a method of the invention, the applied modulation signal on the electrodes of the Mach-Zehnder modulator is superimposed by a pilot tone which is thus superimposed by the modulated light emitted by the Mach-Zehnder modulator. In response to the emitted modulated light, an electrical feedback circuit generates bias control signals for the bias circuit and driver control signals for the driver circuit for regulating the bias signal and the driver signal fed to the Mach-Zehnder modulator.

Abstract: An electric field activated molecular system, preferably bi-stable, configured within an electric field generated by a pair of electrodes is provided for use, e.g., as electronic ink or other visual displays. The molecular system has an electric field induced band gap change that occurs via a change (reversible or irreversible) of the extent of the electron conjugation via chemical bonding change to change the band gap, wherein in a first state, there is substantial conjugation throughout the molecular system, resulting in a relatively smaller band gap, and wherein in a second state, the substantial conjugation is destroyed, resulting in a relatively larger band gap. The changing of substantial conjugation may be accomplished in one of the following ways: (1) charge separation or recombination accompanied by increasing or decreasing electron localization in the molecule; or (2) change of substantial conjugation via charge separation or recombination and&pgr;-bond breaking or making.

Abstract: A piezoelectric optical relay array having one or more array elements. Each array element contains a transparent mirror housing, located at the intersection of two optical paths. A solid slug is moved within a channel passing through the transparent mirror housing by the action of piezoelectric elements. A surface of the solid slug is wetted by a liquid metal to form a reflective surface. The solid slug is moved in or out of the transparent mirror housing to select between the optical paths. When the solid slug is within the transparent mirror housing, an incoming optical signal is reflected from the reflective surface of the liquid metal. The liquid metal adheres to wettable metal surfaces within the channel to provide a latching mechanism.

Abstract: The invention provides an optical modulator which suppresses the loss of a microwave which advances through an electrode and of light which propagates in a waveguide and makes the losses in individual arm waveguides substantially equal to each other to suppress the deterioration of the extinction coefficient to improve the transmission quality. The optical modulator includes a substrate having an electro-optical effect and having a ridge, first and second grooves and first and second banks formed thereon, a Mach-Zehnder optical waveguide, an electrode, and first and second recesses formed at symmetrical positions with respect to the ridge on the first and second banks, respectively. The optical modulator is applied, for example, to a transmission side apparatus for a long distance optical transmission system.