Abstract: The invention relates to a variable optical attenuator constructed as a Mach Zehnder planar lightwave circuit, particularly including a channel waveguide support structure for heat isolation and stress relief to reduce polarization dependent loss (PDL) and power consumption in the device. Power reduction trenches comprise longitudinal segments having small stress relief pillars of cladding material left in between them in the etching process. The waveguides of the MZI are supported by a main pillar structure and integral stress relief pillars which remain after removal of the trenches. The waveguide is surrounded by air on three sides for improved heat isolation. The performance of the present invention shows substantial improvement in PDL and extinction ratio over the prior art continuous trench design, and also, to a smaller degree, over the case where power reduction trenches are not used at all.

Abstract: A device that comprises: a) a first optical waveguide; b) a second optical waveguide; c) an optical coupling region including the first and second optical waveguides, the optical coupling region characterized as having at least one coupling length and comprising a first bias section, a modulation section, and a second bias section arranged such that light propagates serially through the first bias section, the modulation section, and the second bias section; d) a first bias electrode for biasing the first bias section; e) a modulating electrode for applying a modulating voltage to the modulation section, the modulating electrode being positioned to control the refractive index of the first optical waveguide; and f) a second bias electrode for biasing the second bias section.

Abstract: In relation to an optical modulator (e.g., an RZ optical modulator) formed from a plurality of Mach-Zehnder optical modulators, in an attempt to make the optical modulator compact and realize a low drive voltage, the optical modulator is formed by comprising a plurality of Mach-Zehnder optical modulators, each including a substrate exhibiting an electro-optical effect, an optical waveguide formed on the substrate, and electrodes formed in the vicinity of the optical waveguide. The plurality of Mach-Zehnder optical modulators are arranged on the substrate and connected into multistage.

Abstract: An optical modulator is provided with an optical waveguide including an input-side single-mode waveguide for propagating inputted light at single mode, a multi-mode waveguide for propagating the light propagated from the input-side single-mode waveguide at plural guided modes, and an output-side single-mode waveguide for propagating the light propagated from the multi-mode waveguide at single mode to output the light. A lower electrode layer is disposed below the multi-mode waveguide, and an upper electrode is disposed above the multi-mode waveguide. The upper electrode cooperates with the lower electrode layer to apply an electric field to the multi-mode waveguide. A phase of each of the guided modes propagating through the multi-mode waveguide is modulated by applying an electric field to the multi-mode waveguide, and intensity of the light outputted from the output-side single-mode waveguide is modulated by an interference of the phase-modulated guided modes.

Abstract: A reflective optical switch for use in optical systems, such as fiber optic communications networks, is disclosed. The optical switch includes not only signal transmission characteristics, but also signal reflection capability. The optical switch includes a semiconductor substrate having first and second optical signal waveguides disposed thereon. The two waveguides intersect one another at a selected angle to form an intersection region. A thermal element is disposed atop the intersection region and can be activated to alter the index of refraction of a portion of the intersection region. An optical signal passing through the intersection region is diverted from one waveguide to another according to the heating of the intersection region by the thermal element. A reflective component disposed in a terminal end of one of the waveguides reflects selected optical signals back to the source from which they came.

Abstract: An optical circuit including a semiconductor substrate; an optical waveguide formed in or on the substrate; and an optical detector formed in or on the semiconductor substrate, wherein the optical detector is aligned with the optical waveguide so as to receive an optical signal from the optical waveguide during operation, and wherein the optical detector has: a first electrode; a second electrode; and an intermediate layer between the first and second electrodes, the intermediate layer being made of a semiconductor material characterized by a conduction band, a valence band, and deep level energy states introduced between the conduction and valence bands.

Abstract: The present invention provides silicon based thin-film structures that can be used to form high frequency optical modulators. Devices of the invention are formed as layered structures that have a thin-film dielectric layer, such as silicon dioxide, sandwiched between silicon layers. In one aspect of the invention an electrical contact structure is provided. The electrical contact structure comprises a connecting portion that electrically connects an active region of at least one of the silicon layers to a contact portion of the electrical contact structure.

Abstract: A device such as an integrated display device and projector apparatus using said display device for projecting an image on a screen comprises a number of light sources, waveguides, optical switches, micro-lenses and scanning mirrors. The display apparatus consists of said display device, a modulator circuit, an optical switch controller, a scanning mirror controller, a synchronizer and projection optics. This device enables the projector apparatus to be extremely small and to reduce its power consumption in comparison with conventional projectors.

Abstract: The optical device comprises a first substrate 10 having a control circuit formed on; optical waveguide layer 40 formed above the first substrate and having a refractive index changed by electro-optic effect; and second substrates 14a, 14b having prism electrodes 18 for applying voltages to the optical waveguide layer. The control circuit and the prism electrodes are electrically connected to each other via columnar conductors 20. Even in a case where thermal expansion coefficients of the control substrate and of the light deflection substrates are very different from each other, the pins are flexed corresponding to eternal forces, whereby junction is protected from being damaged in the joining processing. Thus, the optical switch can be highly reliable.

Abstract: A planar lightwave circuit and a method of producing such a planar lightwave circuit, the planar lightwave circuit having an element secured thereon. The planar lightwave circuit comprises: a substrate; a trench cut in the substrate; at least one solder pad deposited on a top surface deposited above the substrate; at least one of a waveguide defined in a layer deposited above the substrate and an optical fiber; and an optical element placed within the trench and in optical communication with the at least one of a waveguide and an optical fiber; at least one metal contact configured on the optical element to be adjacent to the metal pad, the solder pad being connected to the metal contact providing physical support to the optical element and an electrical connection between the metal pad and the metal contact.

Abstract: An optical structure is provided. The optical structure includes a substrate having a surface. A modified barium titanate is deposited on the surface of the substrate.

Abstract: A system for matching a optical filter characteristic of a first filter tunable in wavelength with an optical first signal comprises a modulator for modulating at least a part of the first signal with a modulation signal before being applied to the first filter. An analyzing unit derives a control signal for tuning the first filter by analyzing the modulated first signal after passing the first filter in conjunction with the modulation signal.

Abstract: A Mach-Zehnder type electro-optic modulator based, for example, on GaAs/GaAlAs of InP/InGaAsP comprises coplanar stripline (CPS) electrodes, and optical waveguides, disposed on a conducting substrate or a conducting epitaxial layer, wherein the regions underlying the CPS electrodes are selectively rendered insulating by ion implantation to electrically isolate the CPS electrodes.

Abstract: Accordingly, a preferred embodiment of the present invention comprises an electro-optical device having an optical waveguide that includes two optical pathways, wherein the optical waveguide is embedded within the substrate. A bias electrode layer is formed on the surface of the substrate. A buffer layer is formed on at least a portion of the bias electrode layer and the surface of the substrate. An RF electrode layer is formed on the buffer layer. A bias-tee electrically couples the bias electrode layer and the RF electrode layer.

Abstract: A light emissive display having a specular waveguide that propagates short wavelength light and photoluminescent features adjacent to the waveguide that fluoresce, for example, in visible red, green, blue, and mixed colors when selectively coupled with the short wavelength light. The photoluminescent layers emit light primarily and, therefore, efficiently in the direction of an observer only. This light emissive display may be utilized as a planar light source, as patterned information signage, or as a re-configurable information display containing intensity modulated pixels. The light emissive display may be enhanced optically such that only a small portion of ambient light is reflected from the display while preserving the majority of emitted display luminance.

Abstract: A display device and method of operating the display device. The display device comprising a support substrate, a plurality of ring or disk shaped light emitting light emitting resonators placed in a matrix on the support substrate forming a plurality of rows and columns of the light emitting resonators, each of said light emitting resonators having photo-luminescent lumiphore placed in the outer portion of said ring or disk shaped light emitting resonators A plurality of light waveguides positioned on the substrate such that each of the light emitting resonators is associated with an electro-coupling region with respect with to one of the plurality of light waveguides and a deflection mechanism for causing relative movement between a portion of at least one of the plurality of light waveguides and the associated light emitting resonator so as to control when the light emitting resonator is in the electro-coupling region.

Abstract: The index of refraction of waveguide structures can be varied by altering carrier concentration. The waveguides preferably comprise semiconductors like silicon that are substantially optically transmissive at certain wavelengths. Variation of the carrier density in these semiconductors may be effectuated by inducing an electric field within the semiconductor for example by apply a voltage to electrodes associated with the semiconductor. Variable control of the index of refraction may be used to implement a variety of functionalites including, but not limited to, tunable waveguide gratings and resonant cavities, switchable couplers, modulators, and optical switches.

Abstract: A display device and method of operating the display device.

Abstract: A micro-electro-mechanical (MEMs) mirror device for use in an optical switch is disclosed. A “piano”-style MEMs device includes an elongated platform pivotally mounted proximate the middle thereof by a torsional hinge. The middle portion of the platform and the torsional hinge have a combined width less than the width of the rest of the platform, whereby several of these “piano” MEMs devices can be positioned adjacent each other pivotally mounted about the same axis with only a relatively small air gap therebetween. In a preferred embodiment of the present invention specially designed for wavelength switching applications, a greater range of arcuate motion for a mirror mounted thereon is provided by enabling the platform to rotate about two perpendicular axes.

Abstract: An optical interconnection device is provided which comprises an optical waveguide layer, wherein the waveguide layer is equipped with a plurality of electrodes which are independently drive-controllable such that a refractive index distribution is generated in the waveguide layer by drive control of the electrodes to control a propagation state of light in the waveguide layer, and an optical interconnection port is provided on an upper or lower surface or inside of the waveguide layer.

Abstract: An object of the present invention is to provide an optical device, in which a stress applying on ridge sections caused by the difference of thermal expansion between a metal film of which a ground electrode is formed and a substrate is reduced. In order to achieve this, in the optical device of the present invention, the ratio of the volume of a ground electrode portion formed at the position of other groove to the area of opening part of the other groove is smaller than the ratio of the volume to the area of a ground electrode portion formed at the position except the other groove.

Abstract: An electro-optical device capable of modulating the amplitude or phase of an optical output in response to an electrical data or control signal, or of switching it, has reduced frequency-dependence and a better combination of operating voltage and bandwidth. It comprises a body of electro-optically active material, waveguides for passing light through the body, and electrodes for applying an electric field with a frequency in the microwave region to the body, and its transverse geometry is such as to maintain adequate phase velocity matching between optical and microwave frequencies. There is a discontinuity in either the body or at least one of the electrodes such that the direction of the electro-optic effect is reversed for a portion of the length of the device at or near its downstream end.

Abstract: The present invention is directed to Y-branch digital optical switching and optical attenuator devices, which enhance the security of optical communications channels in the event of an electrical power loss.

Abstract: An optoelectronic assembly for an electronic system includes a transparent substrate having a first surface and an opposite second surface, the transparent substrate being thermally conductive and being metallized on the surface. A support electronic chip set is configured for at least one of providing multiplexing, demultiplexing, coding, decoding and optoelectronic transducer driving and receive functions and is bonded to the second surface of the transparent substrate. A first substrate having a first surface and an opposite second surface, is in communication with the transparent substrate via the metallized second surface and support chip set therebetween. A second substrate is in communication with the second surface of the first substrate and is configured for mounting at least one of data processing, data switching and data storage chips.

Abstract: High speed optical modulators can be made of a lateral PN diode formed in a silicon optical waveguide, disposed on a SOI or other silicon based substrate. A PN junction is formed at the boundary of the P and N doped regions. The depletion region at the PN junction overlaps with the center of a guided optical mode propagating through the waveguide. Electrically modulating a lateral PN diode causes a phase shift in an optical wave propagating through the waveguide. Each of the doped regions can have a stepped or gradient doping profile within it or several doped sections with different doping concentrations. Forming the doped regions of a PN diode modulator with stepped or gradient doping profiles can optimize the trade off between the series resistance of the PN diode and the optical loss in the center of the waveguide due to the presence of dopants.

Abstract: A Mach-Zehnder interferometer modulator for modulating a beam of laser light includes a pair of separate waveguides through which the laser light is passed after splitting in a splitting zone and after which the light is recombined in a merge zone. The waveguides are formed in a semiconductor material with one of the electrodes of each pair being formed in a doped layer while the other electrode, the top electrode, is a surface metalisation. The doped layer is trenched so that adjacent electrodes in the doped layer are electrically isolated from one another so that one of the electrodes in the doped layer can be connected with a different electrical polarity to the other electrode in the doped layer thereby permitting the connection of the pairs of electrodes in parallel anti-phase mode.

Abstract: The present invention is an improved electro-optical device comprising a substrate-supported layer of electro-optical material disposed between upper and lower electrodes. Conventional practice has been to make the electrodes thick to minimize electrical loss. Applicants, in contrast, have discovered that the performance of the device can be improved by making the electrodes thin—typically about 2 microns or less and preferably about 0.5 micron or less. While the thin electrodes take a relatively large loss penalty at low frequencies, at higher frequencies the thin electrodes provide a relatively low loss, thus producing a flattened frequency response as compared with thick electrode devices. The device can maintain a wide operating bandwidth at frequencies of interest for optical transmission while reducing the required drive voltage.

Abstract: An apparatus and method is provided which allows transfer of DC electrical power across a transparent or semitransparent medium such as glass. Electrical power transfer is achieved using a suitable optical source (matched visible light or infrared LED or LD arrays are best suited) that illuminates a matched solar cell array on the other side of the medium.

Abstract: Methods of attenuating, delaying the phase, and otherwise controlling an optical signal propagating along a waveguide are provided. According to one method, a variable optical attenuator structure is provided comprising a waveguide core, a cladding, an electrooptic polymer, and a set of control electrodes. The core, the cladding, and the electrooptic polymer are configured such that an increase in the index of refraction of the polymer causes a substantial portion of an optical signal propagating along the waveguide core to couple into a relatively high index region of the electrooptic polymer above the waveguide core, so as to inhibit return of the coupled signal to the waveguide core. Another embodiment of the present invention introduces a phase delay in the coupled optical signal and permits return of the coupled signal to the waveguide core. An additional embodiment contemplates the use of a ridge waveguide structure to enable control of the optical signal.

Abstract: An optical switch of the present invention is for deflecting a light given to an input channel waveguide by first and second optical deflecting sections arranged respectively on the former and latter stages of a slab type optical waveguide section, so that a deflection angle by the first optical deflecting section is symmetrical to that by the second optical deflecting section, to guide the light to a desired output channel waveguide. The first and second optical deflecting sections each includes a half-wave plate between input side upper electrode portions and output side upper electrode portions each of which is formed with prism type electrodes, and the slab type optical waveguide also includes a half-wave plate on the center thereof.

Abstract: The present invention relates to a method of determining a quasi-phase matching efficiency in a periodically poled structure of an optical waveguide, a periodically poled structure of an optical waveguide, and an optical waveguide using the same. It is possible to effectively perform a quasi-phase matching when a width of periodic electrodes is shorter than a coherence length generally used as ½ of a quasi-phase matching period.

Abstract: An optical bandwidth source for generating amplified spontaneous emission (ASE) across a selected wavelength range, the optical bandwidth source including a waveguide having a first end and a second end, and comprising a plurality of separate wavelength gain subsections arranged in a serial configuration between the first end and the second end so as to collectively form an active waveguide between the first end and the second end; wherein each of the wavelength gain subsections is configured to produce ASE across a wavelength range which is less than, but contained within, the selected wavelength range, whereby the plurality of separate wavelength gain subsections collectively produce ASE across the selected wavelength range.

Abstract: In a method of fabricating a traveling wave optical modulator, an optical waveguide structure having an optical waveguide and a signal electrode path extending from a signal input to a termination output is formed. The signal electrode path is modified to include a customized signal electrode having a transmission line characteristic substantially matching a target transmission line parameter value. In another aspect, a traveling wave optical waveguide structure includes an optical waveguide and a signal electrode path. The signal electrode path extends from a signal input to a termination output and is defined by an electrode seed structure. The electrode seed structure is exposed for subsequent electrode formation and has a transmission line characteristic detrimental to proper propagation of an electrical modulation signal.

Abstract: This application describes examples and implementations of optical devices and techniques based on use of whispering gallery mode (WGM) optical resonators that have nonlinear optical materials in multiple sectors where nonlinear coefficients of two adjacent sectors are oppositely poled.

Abstract: The optical device comprises a first substrate 10 having a control circuit formed on; optical waveguide layer 40 formed above the first substrate and having a refractive index changed by electro-optic effect; and second substrates 14a, 14b having prism electrodes 18 for applying voltages to the optical waveguide layer. The control circuit and the prism electrodes are electrically connected to each other via columnar conductors 20. Even in a case where thermal expansion coefficients of the control substrate and of the light deflection substrates are very different from each other, the pins are flexed corresponding to eternal forces, whereby junction is protected from being damaged in the joining processing. Thus, the optical switch can be highly reliable.

Abstract: The intensity of signals in optical networks can be controlled using a variable optical attenuator (VOA). The present invention is a VOA that is particularly well suited for optical networks, for example to provide channel-by-channel normalization of gain control of wavelength division multiplexed signals. The inventive VOA includes a waveguide having a cladding that includes an electro-optical material and electrodes that produce an electric field within the electro-optical material when a voltage difference is applied to the electrodes. The VOA also includes a layer that is parallel to the core of the waveguide and that optically couples to the core to receive light from the attenuated signal. A power meter receives light from the layer as an indication of the amount of light attenuated from the signal and for controlling the voltage to the electrodes.

Abstract: An optical waveguide device 1 has an optical waveguide substrate 19, a supporting body 2 for supporting the substrate 19 and a joining layer 3 for joining the substrate 19 and the supporting body 2. The substrate 19 has a flat plate-shaped main body 4 made of an electro-optic material with a thickness of 30 ?m or smaller and having first and second main faces 4a and 4b opposing each other, an optical waveguide provided on the side of the first main face 4a of the main body 4, and electrodes 7A to 7C provided on the side of the first main face 4a of the main body 4. The joining layer 3 joins the supporting body 2 at a joining face 4d and the second main face 4d of the main body 4. The joining face 2a of the supporting body 2 is substantially flat. Alternatively, the joining layer 3 has a thickness of 200 ?m or lower.

Abstract: A method for separating the orthogonal polarization components of an incident optical signal into two spatially separated output ports is described. The method comprises a Mach-Zehnder interferometer where one of the two branches has a section of waveguide that exhibits form-birefringence. This integrated optic Polarization Beam Splitter (PBS) is broadband, has high extinction ratio, and has characteristics that are tunable.

Abstract: A doped barrier region included in an optical phase shifter is disclosed. In one embodiment, an apparatus according to embodiments of the present invention includes a first region of an optical waveguide and a second region of the optical waveguide. The second region of the optical waveguide includes a higher doped region of material and a lower doped region of material. An insulating region disposed between the first and second regions of the optical waveguide is also included. A first portion the higher doped region is disposed proximate to the insulating region. A dopant barrier region is also included and is disposed between the higher and lower doped regions of the second region of the optical waveguide.

Abstract: The present invention relates to an optoelectrical unit for converting information signals between an electrical signal format and an optical signal format. The proposed unit includes a circuit board, which contains at least one optoelectrical capsule. Each capsule is positioned on the circuit board, such that its footprint towards the circuit board has a smaller area than the area of a largest side of the capsule. Moreover, each capsule includes a feedthrough, which electrically connects one or more components therein to circuitry on the circuit board via a plurality of leads. The feedthrough also contains a shield, which electrically shields at least one signal lead from at least one auxiliary lead. The feedthrough is adapted for positioning the optoelectrical capsule at an arbitrary adapted location on the circuit board.

Abstract: Cascaded optical deflectors are formed from light deflecting elements of an electro-optical material that are individually controlled according to applied voltage differences across the elements. The shape of the elements are determined by the shape of the electrodes on either side of the electro-optical material, while the refractive index is controlled by the sign and magnitude of a voltage difference applied across the elements. In particular, the invention includes light deflection elements that are tilted with respect to one another and that are individually controlled to provide for the deflection of light in an improved manner.

Abstract: An endoscope assembly consisting of an endoscope 622, a light source, 626 and a camera 552 with display 558. The endoscope contains a memory 670 with data that describes the endoscope and its operating characteristics. When the light source is connected to the endoscope with a fiber optic cable 628, the data in the memory are read into a control processor 538a internal to the light source. The control processor, based on the endoscope data configures the light source so that it emits an appropriate amount of light for that endoscope. The light source also sends a control unit 556 of the camera data indicating the type of endoscope to which the camera is attached. Based on this endoscope type data, the control unit processes the image signals generated by the camera head in an appropriate form for the attached endoscope so as to produce appropriate signals for presenting an image on the display.

Abstract: Devices utilize elements carried by a fluid in a microchannel toswitch, attenuate, shutter, filter, or phase shift optical signals. In certain embodiments, a microchannel carries a gaseous or liquid slug that interacts with at least a portion of the optical power of an optical signal traveling through a waveguide. The microchannel may form part of the cladding of the waveguide, part of the core and the cladding, or part of the core only. The microchannel may also have ends or may be configured as a loop or continuous channel. The fluid devices may be self-latching or may be semi-latching. The fluid in the microchannel is moved using e.g., e.g., electrocapillarity, differential-pressure electrocapillarity, electrowetting, continuous electrowetting, electrophoresis, electroosmosis, dielectrophoresis, electro-hydrodynamic electrohydrodynamic pumping, magneto-hydrodynamic magnetohydrodynamic pumping, thermocapillarity, thermal expansion, dielectric pumping, and/or variable dielectric pumping.

Abstract: Disclosed herewith is an optical switch provided on an optical path of an optical waveguide and which switches an advancing direction of a light passed through the optical path. The optical switch includes a movable switching member which switches the advancing direction of the light, and a driving member which electrostatically drives said switching member to move in an arbitrary position so that the light passed through the optical path is guided to different directions.

Abstract: Electro-optical method and device for modulation of light are presented providing a substantially balanced voltage-phase response of the device in two orthogonal polarization directions substantially irrespective of applied voltages. The device comprises a crystal material of a predetermined orientation of the plane of propagation of light therethrough, formed with at least one waveguide channel directed in a predetermined direction, and at least two electrodes accommodated at opposite sides of the waveguide channel. The substantially balanced voltage-phase response is achieved by shifting the electrodes relative to the axis of the waveguide channel a predetermined distance in a certain direction. The device may be designed so as to operate as a phase modulator or an amplitude modulator.

Abstract: An optic switch for cross-connecting input light signals incoming from inlet fiber cables to outlet fiber cables is disclosed that makes use of a holographic filter (5) having a series of preformed different speckle patterns, each in the form of a hologram (H1, H2, . . . ). Associated with input light signals guided past respective inlet passages (4in) of a multimode waveguide (4), different speckle patterns are formed by applying different control voltages across respective electrode pairs (10, 10a) provided thereon. These speckle patterns past a single outlet passage (4out) of the multimode waveguide (4) into which the inlet passages (4in) converge are joined together and enter the holographic filter (5) in which an input light signal is selectively switched, addressed and cross-connected to an outlet waveguide (2) through a region thereof where a formed speckle pattern coincides with a preformed speckle pattern. The multi mode waveguides (4) is formed in, e.g., a LiNbO3 photorefractive substrate (3).

Abstract: The present invention relates to a method for trimming birefringence of an integrated optical device with at least one waveguide having a birefringence characteristic, comprising the steps of providing at least one electrode on top of the waveguide, and applying power equal to or above a predetermined power level to said at least one electrode for causing a change of the refractive indices of the waveguide.

Abstract: A MEMS system including a fixed electrode and a suspended moveable electrode that is controllable over a wide range of motion. In traditional systems where an fixed electrode is positioned under the moveable electrode, the range of motion is limited because the support structure supporting the moveable electrode becomes unstable when the moveable electrode moves too close to the fixed electrode. By repositioning the fixed electrode from being directly underneath the moving electrode, a much wider range of controllable motion is achievable. Wide ranges of controllable motion are particularly important in optical switching applications.

Abstract: A thermo-optic lens of the present invention includes a plurality of parallel heating elements having substantially constant center-to-center spacing and respective dimensions varying from the outermost heating elements to the innermost heating elements, and at least two conductive elements for providing a potential across the heating elements. The dimensions of the heating elements are varied such that a parabolic temperature distribution is generated within the thermo-optic lens. A dispersion compensator of the present invention includes a first and a second waveguide grating, each of the waveguide gratings having a first star coupler, an array of waveguides of increasing path lengths, a first end of each of the waveguides of the array of waveguides optically coupled to the first star coupler, and a second star coupler, a second end of each of the waveguides of the array of waveguides optically coupled to the second star coupler.

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.