Abstract: An optical switch module includes: N first input ports to which a signal is input; M first output ports from which a signal is output; an M×N switch to include N second input ports and M second output ports, and to set a path between the second input ports and the second output ports, the second output ports coupling with the first output ports, respectively; a test-signal input port to which a test-signal is capable of being externally input; an expansion port from which one of the test-signal and the signal from any one of the first input ports is output; and an optical switch to selectively connect at least one of the test-signal and the signal from any one of the first input ports to at least one of the expansion port and any one of the second input ports, wherein both N and M are natural numbers.

Abstract: A Mach-Zehnder interferometer (MZI) filter comprising one or more passive compensation structures are described. The passive compensation structures yield MZI filters that are intrinsically tolerant to perturbations in waveguide dimensions and/or other ambient conditions. The use of n+1 waveguide widths can mitigate n different sources of perturbation to the filter. The use of at least three different waveguide widths for each Mach-Zehnder waveguide can alleviate sensitivity of filter performance to random width or temperature variations. A tolerance compensation portion is positioned between a first coupler section and a second coupler section, wherein the tolerance compensation portion includes a first compensation section having a second width, a second compensation section having a third width and a third compensation section having a fourth width, wherein the fourth width is greater than the third width and the third width is greater than the second width.

Abstract: A node in a wavelength division multiplexing (WDM) system is provided, which includes: a colorless optical transmitter, a first arrayed waveguide grating, a first waveband filter configured to divide an input optical signal into M sub-signals of different wavebands and output to a first optical switch, and a first optical coupler/a first optical combiner. A transmit end of the colorless optical transmitter is coupled to an input end of the first waveband filter via the first arrayed waveguide grating. The first optical switch is configured to connect an output end of the first waveband filter to an input end of the first optical coupler/the first optical combiner according to a control signal. An output end of the first optical coupler/the first optical combiner is coupled to an optical transmission path.

Abstract: In order to improve the reliability of a reconfigurable optical add/drop multiplexing (ROADM) device, provided is an optical add/drop device that comprises the following: a first wavelength selection unit and a second wavelength selection unit that can select and output an optical signal of a prescribed wavelength from among inputted optical signals; a first branching unit that selectively outputs a first signal being an optical signal that has been inputted from a first terminal station on a main route to the first wavelength selection unit and the second wavelength selection unit; a second branching unit that selectively outputs a second signal being an optical signal that has been inputted from a second terminal station on a sub-route to the first wavelength selection unit and the second wavelength selection unit; and a first output unit that can selectively output to the second terminal station, as a third signal, either the optical signal outputted by the first wavelength selection unit on the basis of t

Abstract: An example system can comprise an optical circuit switch. An input port module can receive an input optical signal comprising a plurality of input components, perform an optical to electrical to optical conversion on the input optical signal, multiplex the plurality of input components to an internal optical signal, and transmit first internal optical signal on a first internal waveguide. A switch module can receive the internal optical signal and transmit the transformed internal optical signal on a second internal waveguide according to a predefined control algorithm, which can permit any input component to be mapped to any frequency group and sent to any output component. An output port module can receive the internal optical signal, perform another optical to electrical to optical conversion on the internal optical signal, and demultiplex the internal optical signal to an output optical signal comprising a plurality of output components.

Abstract: A communications system may include a first active circuit device and a waveguide coupled to the first active circuit device. The waveguide may include a plurality of passive optical devices spaced apart from one another and arranged along an optical path, and an interconnect structure interconnecting the passive optical devices and integrally formed as a unitary body with the passive optical devices. Furthermore, the interconnect structure may have an opening therethrough aligned with the optical path.

Abstract: A fiber optic tap system includes a first receiver module having an input port configured to receive an optical fiber. The first receiver module is operable to convert a received optical signal to an electrical signal. A first transmitter module is coupled to receive the electrical signal from the first receiver module and convert the received electrical signal to an optical signal. The first transmitter module has an output port for outputting the optical signal. A first tap module is coupled to receive the electrical signal from the first receiver module.

Abstract: An optical device has a photonic IC having a modulator block and a photodetector block for transmitting and receiving optical signals via multiple channels, and a wiring board to transmit and receive electrical signals to and from the photonic IC, multiple electrical wirings formed on the wiring board being associated with the multiple channels, wherein the photonic IC has a first optical waveguide set extending from an output end of the modulator block to an output port of the photonic IC and a second optical waveguide set extending from an input port of the photonic IC to an input end of the photodetector block, the optical waveguides are arranged in the shortest paths for the respective channels in the first and the second optical waveguide sets, and the lengths of the electrical wirings are set so as to compensate for a difference in optical waveguide length among the channels.

Abstract: A data center network system and a signal transmission system, where the signal transmission system includes one hub device, at least two switches, multiple colored optical modules, at least two multiplexers/demultiplexers, and at least two servers. The hub device, the at least two switches, the multiple colored optical modules, the at least two multiplexers/demultiplexers, and the at least two servers form a star network topology structure.

Abstract: A wavelength routing SW is a large-scale optical switch device of a conventional technique, and it requires as many wavelength-tunable light sources as the number of input ports. For the wavelength-tunable light sources to achieve a stable oscillating operation across a wide wavelength range, a complicated control mechanism is necessary. This has been an obstacle in providing a large-scale optical switch device in terms of cost and circuit scale. A wavelength routing SW in the present disclosure includes N wavelength group generators, a splitting-selection unit, and MN tunable filters. Each wavelength group generator includes M fixed-wavelength light sources. Inexpensive general-purpose devices that require no control mechanism for wavelength tuning can be used as the fixed-wavelength light source. The channel loss in the optical switch device can also be reduced by using light sources with a limited narrow range of tunable wavelengths and the wavelength-dependent output port selecting function of an AWG.

Abstract: A refractive index n of a dielectric material is larger than a refractive index of the outside in a lateral direction X and/or a vertical direction Y perpendicular to an electromagnetic wave travelling direction Z, the inside of a waveguide-path has slow electromagnetic wave propagation velocity, compared to an area on the outside, the maximum dimension in the lateral direction and/or the vertical direction of the waveguide-path has a dimension which is specified by a formula below. The formula is: tan(ksa/2)=kf/ks, or tan(ksa/2)=?ks/kf. Here, ks: propagation constant of an electromagnetic wave low-speed area, kf: propagation constant of an electromagnetic wave high-speed area, and a: maximum dimension in the X direction and/or the Y direction of the waveguide-path.

Abstract: A laser scanner system that steers laser beams with GHz throughput and precision is based on switching (thin) films that are either metallic, or stacks of alternating dielectric films. The films are arranged with a slight tilt angle to the incident laser beam. They change their optical properties under electrical loads and become highly reflective to reflect the beam to a certain direction depending on the tilt angle of the switched film. In the area of laser based machining it will be possible to produce with a far higher throughput and precision than with conventional galvanometer based systems. The scanner can be also used in bar code scanners or in laser based TV systems. A new adaptive wavefront correction element can be achieved using switching films arranged in an xy matrix. Many applications of such a distortion correction element exist in adaptive optics.

Abstract: A process of assembling an optical receiver module that receives a wavelength multiplexed signal is disclosed. The process includes a step of sequentially mounting a wavelength selective filter (WSF), a prism, a mirror, and first and second optical de-multiplexers (o-DeMuxes) each on the carrier. The WSF transmits a first wavelength multiplexed signal but reflects a second wavelength multiplexed signal. The prism includes first and second surfaces, where the first surface reflects the wavelength multiplexed signal toward the WSF, while the second surface receives a second wavelength multiplexed signal coming from the WSF. The mirror reflects the first wavelength multiplexed signal transmitting through the WSF. The first and second o-DeMuxes de-multiplex the first and second wavelength multiplexed signals.

Abstract: The ends of sensing and interrogating multicore fibers are brought into proximity for connection in a first orientation with one or more cores in the sensing fiber being paired up with corresponding one or more cores in the interrogating fiber. Optical interferometry is used to interrogate at least one core pair and to determine a first reflection value that represents a degree of alignment for the core pair in the first orientation. The relative position is adjusted between the ends of the fibers to a second orientation. Interferometry is used to interrogate the core pair and determine a second reflection value that represents a degree of alignment for the core pair in the second orientation. The first reflection value is compared with the second reflection value, and an aligned orientation is identified for connecting the sensing and interrogating fibers based on the comparison.

Abstract: A display apparatus includes a display section that displays an image and a controller that controls the display apparatus based on setting information to cause the display section to display the image and changes the setting information from first setting information to second setting information in accordance with a first instruction. In a state in which the controller has changed the setting information from the first setting information to the second setting information and causes the display section to display a first image based on first image information from the first input section, and when the controller receives a second instruction to cause the display section to display a second image based on second image information from the second input section, the controller changes the setting information from the second setting information to the first setting information and causes the display section to display the second image.

Abstract: Near-to-eye devices with steerable phased arrays are provided. In some configurations, a device comprises waveguides, e.g., color plates, that are individually formed to couple a corresponding color output of a micro-display engine and project an image into a human vision system. Some configurations include steerable phased arrays for generating light defining a field of view of image content. The generated light is aligned with light from a real-world view to create an output that concurrently displays the real-world view with the field of view of the image content. The light from the steerable phased arrays is directed through one or more waveguides to an output region of the one or more waveguides. The light from the real-world view can pass through transparent portions of waveguides in a manner that aligns a rendering of the image content with the light from the real-world view to create augmented reality views.

Abstract: A system and method for controlling the energy flux of a light beam (carrier wave) relies on the manipulation of a light beam's Poynting vector to switch the light beam from one optical waveguide to another. A modulator positioned between the two waveguides has an index of refraction n+ik wherein ik is a loss/gain component. It is the manipulation of this loss/gain component ik by an external stimulus which causes anisotropic changes in orthogonal components of the light beam's Poynting vector. This, in turn, causes changes in the propagation distance of the light beam (carrier wave) over a length L along the waveguides that switch the light beam from one waveguide to the other.

Abstract: An optical switch module includes: N first input ports to which a signal is input; M first output ports from which a signal is output; an M×N switch to include N second input ports and M second output ports, and to set a path between the second input ports and the second output ports, the second output ports coupling with the first output ports, respectively; a test-signal input port to which a test-signal is capable of being externally input; an expansion port from which one of the test-signal and the signal from any one of the first input ports is output; and an optical switch to selectively connect at least one of the test-signal and the signal from any one of the first input ports to at least one of the expansion port and any one of the second input ports, wherein both N and M are natural numbers.

Abstract: A method of automated testing and evaluation of a node of a communications network, the method comprising: a management computer interacting with the node to discover fiber trails within the node that can be safely tested; and the management computer interacting with the node to test at least continuity of each identified fiber trail that can be safely tested.

Abstract: An optical transmission module according to the disclosure comprises a first optical transmission line, a second optical transmission line, and a ferrule. The first optical transmission line has a first end face. The second optical transmission line has a second end face opposed to the first end face of the first optical transmission line. An end of the first optical transmission line is situated inside the ferule, and the ferule has a light-transmittable intermediary portion situated between the first end face and the second end face.

Abstract: A data center network device provides configurations where the port density can be increased by incorporating multiport transceivers within the device and the use of high density fiber connections on exterior panels of the device. The device also permits dynamically reassigning fiber connections to convert from single fiber connection paths to higher rate bonded fiber paths while at the same time making more efficient use of the fiber interconnections.

Abstract: Optical communication systems and methods using coherently combined optical beams are disclosed. A representative system includes a first data source for sending first data at a first frequency of a first optical beam to a first aperture, and at a second frequency of a second optical beam to a second aperture. The system further includes a second data source for sending second data at a third frequency of a third optical beam to the first aperture, and at a fourth frequency of a fourth optical beam to the second aperture. The system also includes a first interleaver of the first aperture configured to interleave the first data at the first frequency and the second data at the third frequency; and a second interleaver of the second aperture configured to interleave the first data at the second frequency and the second data at fourth frequency.

Abstract: A method and apparatus for dissipating an electrostatic charge from an optical element are described. An apparatus includes the optical element, a microelectromechanical system (MEMS) device located proximate to the optical element, and a conductive coating over the optical element, wherein the conductive coating is substantially transparent, and wherein the conductive coating dissipates the electrostatic charge.

Abstract: A method, apparatus and optical device for detecting a relationship between an evanescent field and Goos-Hänchen shift, said method comprising: obtaining a potential field function of an evanescent field acting on total-reflection light according to physical meanings of a force function and the potential field function of light in the evanescent field (S101); obtaining a wave function of the perturbed total-reflection light by means of the Schrödinger equation by combining with the potential field function of the evanescent field acting on total-reflection light (S102); and comparing the wave function of the perturbed total-reflection light with a wave function of free total-reflection light with no action from the evanescent field, and determining a momentum gained by the total-reflection light under the action of the evanescent field, which is the same in nature as a momentum of the evanescent field (S103).

Abstract: Telecommunications switches are presented, including expandable optical switches that allow for a switch of N inputs×M outputs to be expanded arbitrarily to a new number of N inputs and/or a new number of M outputs. Switches having internal switch blocks controlling signal bypass lines are also provided, with these switches being useful for the expandable switches.

Abstract: The present invention is based on a two-dimensional photonic crystal where are inserted defects that originate two waveguides and one resonant cavity. An electromagnetic signal that crosses the device is confined in the interior of the defects, due to the photonic band gap associated with the periodic structure that surrounds it. Its main function is the control of the flux of an electromagnetic signal over a communication channel, blocking (state off) or allowing (state on) the passage of the signal. It also promotes the change in the propagation direction of an electromagnetic signal by an angle of 120 degrees, providing greater flexibility in the design of integrated optical systems. The working principle of the device is based on the excitation of dipole modes in its resonant cavity, accordingly to the application of an external DC magnetic field on the magneto-optical material that constitutes it. In states on and off the magneto-optical material is magnetized and nonmagnetized, respectively.

Abstract: An artificial illumination device for generating natural light similar to that from the sun and the sky comprises a direct-light source comprising a first emitting surface and configured to produce, from primary light, direct light exiting the first emitting surface into a direct-light direction at low divergence, the direct-light source comprising a plurality of pairs of a first light-emitting device positioned upstream the first emitting surface and configured to emit the primary light and a collimator configured to collimate the primary light emitted by the first light-emitting device along the direct-light direction; and a diffused-light generator configured to cause diffused light at a second emitting surface.

Abstract: A portion of an optical waveguide extending laterally within a photonic integrated circuit (PIC) chip is at least partially freed from the substrate to allow physical displacement of a released waveguide end relative to the substrate and relative to an adjacent photonic device also fabricated in the substrate. The released waveguide end may be displaced to modulate interaction between the photonic device and an optical mode propagated by the waveguide. In embodiments where the photonic device is an optical coupler, employing for example an Echelle grating or arrayed waveguide grating (AWG), mode propagation through the coupler may be modulated via physical displacement of the released waveguide end. In one such embodiment, thermal sensitivity of an integrated optical wavelength division multiplexer (WDM) is reduced by displacing the released waveguide end relative to the coupler in a manner that counters a temperature dependence of the optical coupler.

Abstract: Preparation cell systems and methods are described herein. One example of a system for a preparation cell includes a laser coupled to a fiber bundle comprising a plurality of fibers, a preparation cell to prepare a state of laser light received by the fiber bundle, and an exiting fiber bundle coupled to the preparation cell.

Abstract: An optical transceiver for controlling a steering angle between a receive light beam and a transmit light beam includes an optical beam coupling device. The optical beam coupling device comprises a plurality of optical elements configured to control a steering angle between the receive light beam received by the optical beam coupling device along a first line of sight (LOS) and the transmit light beam that is output from the optical beam coupling device along a second LOS different from the first LOS, wherein both the receive light beam and the transmit light beam pass through the plurality of optical elements. The plurality of optical elements have a set of combinations for different positions of each of the optical elements, wherein each position in the set of combinations induces a different steering angle between the transmit light beam and the receive light beam.

Abstract: In various embodiments, one or more prisms are utilized in a wavelength beam combining laser system to regulate beam size and/or to provide narrower wavelength bandwidth.

Abstract: An integrated circuit includes a transmitting circuit configured to be coupled to a physical serial interface having a bit width. The transmitting circuit is configured to transmit, via the physical serial interface, a frame including multiple aligned flits all of an equal fixed length that is an integer multiple of the bit width of the physical serial interface. The multiple flits include both a control flit specifying at least a command to be performed by a recipient of the command and a data flit providing data to be operated upon through performance of the command. The control flit includes a data protection code computed over the control flit and a data flit of a previously transmitted frame.

Abstract: An electronic device disclosed herein includes a mirror controller configured to generate a drive control signal, with a drive circuit configured to generate a drive signal for a movable mirror based upon the drive control signal. A sensing circuit is configured to sense the drive signal. The mirror controller is further configured to adjust the drive control signal as a function of the sensed drive signal.

Abstract: A device is provided that includes a first waveguide configured to guide propagation of RF waves inside the first waveguide. A first side of the first waveguide is configured to emit an evanescent field associated with the propagation of the RF waves inside the first waveguide. The device also includes a second waveguide having a second side positioned within a predetermined distance to the first side of the first waveguide. The second waveguide is configured to guide propagation, inside the second waveguide, of induced RF waves associated with the evanescent field from the first waveguide. The device also includes a first probe coupled to the first waveguide and configured to emit the RF waves for propagation inside the first waveguide. The device also includes a second probe coupled to the second waveguide and configured to receive induced RF waves propagating inside the second waveguide.

Abstract: A laser beam steering device and a system including the same are provided. The laser beam steering device includes a waveguide through which a laser beam passes, and a cladding layer disposed on the waveguide. The cladding layer has a refractive index which changes according to an electrical signal applied thereto and thus a phase of a laser beam passing through the waveguide may be changed.

Abstract: An optical product can reproduce a first 3D image of at least part of a first 3D object and a second 3D image of at least part of a second 3D object. The optical product comprises a surface configured, when illuminated, to reproduce by reflected or transmitted light, the first 3D image without reproducing the second 3D image at a first angle of view, and the second 3D image without reproducing the first 3D image at a second angle of view. Each portion of first portions can correspond to a point on a surface of the first 3D object, and comprise first non-holographic features configured to produce at least part of the first 3D image. Each portion of second portions can correspond to a point on a surface of the second 3D object, and comprise second non-holographic features configured to produce at least part of the second 3D image.

Abstract: An optical switch (10) comprising: input ports (12, 14) arranged to receive optical signals from directions D1 to Dn; output ports (16, 18) arranged to output optical signals to the said directions; drop ports (20); add ports (22); a first switch array (24) arranged to receive from a first said input port (12) optical signals at a plurality of wavelengths, and comprising switch elements (26) each arranged to selectively direct optical signals to a respective drop port.

Abstract: Disclosed herein is a method of optical modulation, the method comprising irradiating an optical switch with a control beam at a first control time and irradiating the optical switch with a signal beam at a signal time. The transmitted intensity of the signal beam in a direction depends on the delay time between the first control time and the signal time and the transmitted intensity of the signal beam in the direction is detectably different than a static signal. The optical switch comprises a nanorod array, the nanorod array comprising a plurality of nanorods extending outwardly from a substrate.

Abstract: An integrated non-reciprocal polarization rotator comprises a substrate, a Faraday crystal, a first waveguide, and a second waveguide. The substrate has a recess extending to a predetermined depth. The Faraday crystal is mounted in the recess and optically coupled with the first waveguide and the second waveguide.

Abstract: A communication system that can be used, e.g., to provide high-speed access to the servers of a data center. In an example embodiment, the communication system transports data using WDM optical signals. The downlink WDM signals have some WDM components that are modulated with data and some WDM components that are not modulated with data. The uplink WDM signals are generated at the server end of the system by modulating with data the unmodulated WDM components received through the downlink. Appropriately connected wavelength multiplexers, wavelength demultiplexers, and/or optical filters can be used to properly apply the various modulated WDM components to the corresponding optical receivers and the unmodulated WDM components to the corresponding optical transmitters. The resulting system architecture advantageously enables, e.g., the use of a single, conveniently located multi-wavelength light source to provide carrier wavelengths for both uplink and downlink optical traffic.

Abstract: A Micro-Electro-Mechanical Systems (MEMS) actuator can rotate other, discrete optical elements that may be dimensionally large (especially in terms of thickness), may be of relatively large mass, and may be made of dissimilar materials (i.e., some material other than silicon). The rotating optical element may be reflective or transmissive. The MEMS actuator is used in multiple additional embodiments, allowing the integration of multiple optical functions into a single optical component, for a variety of applications. These optical functions include optical switching, optical attenuation, tunable optical filtering, the adjustment of the phase angle of an optical signal, and the detection or receiving of an optical signal or optical power level.

Abstract: An optical selector arrangement (22), comprising: a first set of optical ports (30), having a first number of optical ports, the first number being greater than or equal to 2; a second set of optical ports (42), having a second number of optical ports, the second number being greater than the first number; the second set of optical ports being for communicating with the first set of optical ports, a selector interface (40) for the optical selector arrangement, the selector interface comprising the second set of optical ports (42), a part of the optical selector arrangement functioning as a selector (44), the selector being arranged to selectively optically couple the first set of optical ports (30) to a set of ports of the second set of optical ports (42) of the selector interface, the selector (44) being rotatable relative to the selector interface (40) to facilitate the selection by optically aligning the first set of optical ports (30) to the second set of optical ports (42) of the selector interface (40);

Abstract: It is difficult to improve the wavelength-band utilization rate of an optical network as a whole while operating the optical network stably; and therefore, an optical network controller according to an exemplary aspect of the present invention includes optical wavelength region setting means for setting a wavelength region in an optical transmission line between a plurality of optical nodes composing an optical network using wavelength division multiplexing system dividing the wavelength region into consecutive regions of a first wavelength region and a second wavelength region; optical path setting means for setting a first optical path in the first wavelength region and a second optical path in the second wavelength region, the second optical path differing from the first optical path in a route; and control unit for instructing the plurality of optical nodes on a central wavelength and a usable band of signal light for the optical node to transmit based on a setting by the optical path setting means.

Abstract: The present disclosure relates to wavelength selective switches. In one embodiment, a wavelength selective switch may include a liquid crystal (LC)-based attenuation switching device that has an LC switching module to switch an incident beam to one of a plurality of output paths. The LC switching module may include one or more LC switching cells. The LC-based attenuation switching device further includes a mirror to reflect the beam from the LC switching module so as to output the beam through a corresponding output port, and a temperature compensation module provided on a side of the mirror opposite to the LC switching module. The temperature compensation module may be configured to alter curvature of the mirror as temperature changes so as to compensate for deformation of the LC switching cells due to the temperature change.

Abstract: An integrated optical collimator device includes an optical fiber extending from a first end to a second end. The first end of the optical fiber is configured to be coupled to a light source or a light receiver. A housing is coupled to the ferrule and extends radially over the ferrule. A collimating lens is positioned in the housing proximate the second end of the optical fiber. A polarizer element is positioned within the housing proximate the collimating lens.

Abstract: A method for achieving alignment and optical switching of a liquid crystal (LC) layer that is deposited on chalcogenide glass (ChG). Direct brushing of ChG produces an effective LC alignment layer. Also disclosed is the related waveguide assembly for achieving alignment and optical switching of a liquid crystal (LC) layer deposited on chalcogenide glass (ChG).

Abstract: Light from an array of laser light sources are spread to cover the modulating face of a DMD or other modulator. The spread may be performed, for example, by a varying curvature array of lenslets, each laser light directed at one of the lenslets. Light from neighboring and/or nearby light sources overlap at a modulator. The lasers are energized at different energy/brightness levels causing the light illuminating the modulator to itself be modulated (locally dimmed). The modulator then further modulates the locally dimmed lights to produce a desired image. A projector according to the invention may utilize, for example, a single modulator sequentially illuminated or separate primary color modulators simultaneously illuminated.

Abstract: This invention removes the need to provide temperature control for an optical time delay chip, which is usually provided by a thermo-electric-cooler, in order to significantly reduce the power dissipation of the device and allow ‘uncooled’ operation. Uncooled operation is achieved by monitoring the temperature of the chip, and changing the tuning of each microresonator within the device in order to continue providing the required time delay as the temperature is varied. This invention takes advantage of the fact that microresonators provide a series of resonant wavelengths over a wide wavelength range, so that the closest resonance wavelength below the operating wavelength can always be tuned up to that wavelength. When the device temperature changes, this is accounted for by both the choice of resonance wavelengths and the tuning for each of the microresonators in the device, in order to keep the correct tunable delay.

Abstract: Consistent with the present disclosure, both arms of an MZ interferometer are “double-folded” and are bent in at least two locations to define first and second acute inner angles. Accordingly, the arms of the MZ interferometer may have substantially the same length, and, further, the MZ interferometer has a more compact geometry. In one example, the arms parallel each other and have a serpentine shape, and, in a further embodiment, the arms parallel one another and have a Z-shape. Accordingly, since the temperature of a PIC upon which the MZ interferometer is provided does not vary significantly over such short distances, the temperatures of both arms is substantially the same.

Abstract: In accordance with the present invention the switching element of an optical switch for switching/modulating an optical signal from one optical waveguide to another is a reverse bias diode. More particularly, the diode is itself an optical waveguide that has been doped to create a predetermined depletion width, Wd, between the N-type and IP-type regions of the diode. In operation, an optical signal is input into the waveguide/diode in a manner that generates a second order mode for the optical signal. The second order mode optical signal then transits the waveguide/diode back and forth through the depletion width Wd. A switching voltage, V?, which is selectively applied to the waveguide/diode, can then alter the depletion width Wd of the waveguide/diode. Consequently, the propagation interference distance, ?c, of the waveguide/diode will also be changed, to thereby direct the optical signal from one output optical filter to another.