Abstract: Broadband optical switches based on adiabatic couplers having a pair of asymmetric waveguides with variable curvature sections include in a 2×2 configuration based on a Mach-Zehnder interferometer two such adiabatic couplers, and in a 1×2 or 2×1 configuration an adiabatic coupler and an Y-splitter. Each adiabatic coupler includes two waveguide branches of different but constant widths having curved sections with varying radii, separated over a coupling length by a changing spacing therebetween and blending in an asymmetric intersection area, and two symmetric branches. In the 2×2 switch, the two adiabatic couplers face each other with their respective symmetric branches, and are connected by the two identical arms along a main propagation axis in a mirror image. The utilization of the variable curvature adiabatic couplers in silica MZI switches on a silicon substrate provides switches with an exceptional broadband range (1.2-1.

Abstract: An optical fiber and methods of processing and manufacturing an optical fiber comprising a core, a cladding and a coating covering a segment of the cladding proximate to an end of the optical fiber are presented where patterned apertures are provided in the coating such that a portion of light propagating in the cladding escapes through the patterned apertures of the coating. The patterned apertures allow non-confined light to escape from the cladding in the coating region to provide reduced absorption of the non-confined light by the coating.

Abstract: Provided are a multi-wavelength optical transceiver module and a multiplexer/demultiplexer using a thin film filter. The multi-wavelength optical transceiver module includes: a PLC platform, on which a predetermined optical waveguide unit is formed and an optical transmitter is mounted; an optical fiber coupled to one side of the PLC platform to transmit a predetermined light; a plurality of thin film filters coupled to another side of the PLC platform to separate input optical wavelengths; and an optical receiver coupled to one side of the thin film filters to receive light that is input from the optical fiber and transmits the thin film filters, thereby enabling mass production of the optical transceiver module with low cost.

Abstract: In an optical grating device, a grating arrangement receives different wavelength output signals from a plurality of radiation sources at input ports thereof, and generates therefrom a multiplexed wavelength output signal at a zero diffraction order output port of the grating arrangement. Additionally, the gating arrangement generates at least one predetermined wavelength output signal at one of a group consisting of a separate predetermined location in an at least one of a symmetric non-zero diffraction order of the grating arrangement, within the grating arrangement itself, and a combination thereof. A separate power tap is coupled to detect the power of a separate one of the at least one predetermined wavelength output signal from the grating arrangement.

Abstract: An optical transceiver is equipped with at least one coupling lens which condenses reception signal light from an optical medium and condenses transmission signal light to the optical medium, an optical plate which passes the reception signal light and reflects the transmission signal light, a light receiving element which receives the reception signal light passed through the optical plate, and a light emitting element which transmits the transmission signal light so as to be reflected by the optical plate, wherein an emission port of the transmission signal light of the light emitting element is arranged at a position to enable the transmission signal light from the light emitting element to form an image in the optical medium via the optical plate and the coupling lens, and wherein the emission port of the transmission signal light of the light emitting element is arranged in a direction that makes the incident angle formed on the optical plate by the beam center line of the transmission signal light trans

Abstract: An optical waveguide monitor equipped with an output light monitor having a decreased restriction in the dimensions and form thereof, a high reliability and a low production cost includes an optical waveguide element (having a plurality of surface waveguide portions, a connecting portion for converging and connecting the surface waveguide portions and an output light-outputting waveguide portion connected to the connecting portion each formed on a dielectric substrate plate; an output light optical fiber connected to an output end of the output light-outputting waveguide portion, a reinforcing capillary for reinforcing a connection between the optical waveguide element and the output light optical fiber and a monitoring light receiving means, wherein the reinforcing capillary has a hole or groove for containing and supporting the output light optical fiber therein, a connecting face thereof bonded to an output end face of the substrate, and a terminal surface opposite to the connecting face, to thereby enable

Abstract: An optoelectronic assembly (300) includes a laser (102) for emitting light along a main optical path. Beam splitters (110, 114) split a proportion of light from the main optical path and the split light is guided by optical light guides (310) to a photodiode array (302). The light guides (310) are mouldable and substantially rigid and can be co fabricated as a single assembly including fiducials to facilitate positioning on a substrate (124) of the assembly (300). By having the array (302) adjacent the periphery of the substrate (124), wirebonds (308) need only be provided directly from the array (302) to a feed-through (130), and electrical tracks on the substrate and ceramic blocks for mounting the photodiodes are eliminated, as is individual placement of the ceramic blocks on the substrate.

Abstract: Optical systems are provided. A representative optical system includes an optical transceiver with an optical source and an optical receiver. The system also includes an optical waveguide. At least one of the optical source and the optical receiver is optically coupled to an intermediate portion of the optical waveguide. The optical source provides optical signals for propagation by the optical waveguide, and the optical receiver receives optical signals propagated by the optical waveguide. Methods, optical transceivers and other systems also are provided.

Abstract: Photonic signals of high bandwidth are input into a winding of optical fiber. The winding of fiber has winds of fiber that are adjacently disposed and that form a substantially linear outer surface of the winding. A series of optical taps are defined in the optical fiber along this surface. The fiber includes an inner core surrounded by an outer layer. The taps comprise a diminished outer layer section of the fiber. It is from these taps that optical energy is released from the fiber.

Abstract: A polarization compensated planar waveguide branch is disclosed having a planar optical trunk waveguide for transporting a linearly un-polarized optical signal having TE and TM modes. A planar optical branch waveguide, capable of supporting TE and TM modes is optically coupled to the trunk waveguide such that at least a portion of an optical signal propagating within the trunk waveguide will couple into the branch waveguide with an undesired imbalance, having stronger TM mode coupling than TE mode coupling for the at least the portion of the optical signal which couples into the branch waveguide from the trunk waveguide.

Abstract: A method and apparatus is provided for power balancing an optical signal wavelength to be added to an OADM having at least one drop port and at least one add port. The method begins by monitoring a power level of a first signal wavelength being dropped on the drop port and a power level of a second signal wavelength being added on the add port. The power level of the first signal wavelength is compared to the power level of the second signal wavelength. Based on the step of comparing, the optical attenuation is adjusted along the add port so that the power level of the second signal wavelength becomes substantially equal to the power level of the first signal wavelength.

Abstract: A circuit board has embedded optical fibers terminating in fiber ends which face into holes defined in the circuit board and optoelectronic emitter or detector modules mounted in the holes in optical coupling with the fiber ends. Each module is electrically connected to circuit traces on the circuit board and is optically coupled to one or more optical fibers terminating on a side surface of the hole. The modules have an optical axis oriented into the hole and a reflector supported in the hole for optically coupling the photo emitter/detector module with the fiber ends on the side surface of the hole.

Abstract: An optical fiber, which is provided in each of channels of an optical fiber array disposed on V-grooves, has a portion (reflecting section) at which a core is cut out at an intermediate position of the optical fiber. The reflected light, which is split from a signal light transmitted in the core of the optical fiber on the basis of a refractive index difference at the reflecting section, is obtained through a index matching layer provided outside a clad of the optical fiber. The reflected light is monitored by a photodetector of a photodetecting array.

Abstract: A broadband optical fiber tap for transferring optical energy out of an optical fiber having an optical fiber with a primary and secondary microbends for the purpose of coupling optical energy into the higher-order modes of the fiber, and a reflecting surface formed in the cladding of the fiber and positioned at an angle so as to reflect, by total internal reflection, higher-order mode energy away from the optical fiber. In the preferred embodiment, the two microbends are spaced apart by a distance approximately equal to one-half of the intermodal beat length for LP01 and LP11 modes of a single-mode fiber.

Abstract: A method and apparatus for monitoring fiber optic communications involves providing a space between a first end of a first optical fiber and a second end of a second optical fiber. A reflector is movable between a retracted position and an active position. In the active position, the reflector is positioned in the path of an optical signal beam passing through the space between the first optical fiber and the second optical fiber to reflect a portion of the optical signal beam as a tap signal. The reflector is selectively moved between the retracted position and the active position. This enables the tap signal to be selectively turned off and on. It also enables the portion of the optical signal beam reflected to be selectively adjusted.

Abstract: An exemplary WDM coupling device may include optical fibers. The coupling device may also include region(s) having varying coefficients of thermal expansion. During a temperature variation, one or more of the region(s) may alter in size to substantially cancel temperature-dependent changes associated with the WDM coupling device.

Abstract: The present invention is directed to the creation of optical waveguiding devices from standard optical fibers by the creation of zones of permanently altered refractive index characteristics therein. A high intensity femtosecond laser beam is focused at a predetermined target region in the fiber so as to soften the glass material at the target region. After aligning the focal region with the target region in the fiber there will be relative movement between the focal region and the fiber, which has the effect of sweeping the focal region across the fiber in a predetermined path. The result is a zone within the fiber in which the refractive index characteristics of the fiber have been permanently altered so as to control amplitude, phase, spatial propagation or polarization states of light within the material.

Abstract: An optical distributor includes an optical-signal input port, a light receiving device, a light emitting device, a light splitter, and optical signal output ports. The light receiving device converts an optical light signal input to the optical-signal input port into an electric signal. The light emitting device converts the electric signal into an optical signal. The optical splitter 14 splits the converted optical signal into two optical signals. The optical-signal output ports output the split optical signals. The light receiving device includes a light receiving element, a pre-amplifier, and a limiting amplifier. The light emitting device includes a light-source drive element and a light emitting element.

Abstract: An inventive optical functional device includes: two optical waveguides having mutually different equivalent refractive indices; and a connection through which the two optical waveguides are connected along an optical axis. The two optical waveguides are provided as a first optical waveguide, and a second optical waveguide having an equivalent refractive index lower than that of the first optical waveguide, respectively. The connection, through which the first and second optical waveguides are connected along the optical axis, is formed by selectively enlarging the width of the second optical waveguide, and is allowed to function as a multimode interference waveguide. The connection allows multimode propagation of a light passing through the second optical waveguide, and allows the light to be coupled into the first optical waveguide.

Abstract: An optical waveguide such as an optical fiber extends across a semi-rigid substrate or optical back plane and is made of conformal materials having indices of refraction selected to provide substantially total internal reflection of light transmitted within a core. An optical pin is made of substantially rigid optically transmissive materials. A receptacle in the substrate or optical backplane removably receives and holds the optical pin to allow a beveled terminal end of the pin to penetrate the core of the optical fiber to establish a gap-less interface that provides an optical path between the core and the pin.

Abstract: An all-optical bistable device, comprising: a splitting device having first and second inputs and first and second outputs, for receiving first light beam at the first input and directing the first beam as second and third beams propagating through respective first and second outputs; first optical path between the first output and the second input and second optical path between the second output and the second input for creating combined optical path for the first and second beams at the second input; the combined optical path includes a saturable optical amplifier for enhancing and diminishing one of the second and the third beams for driving the optical amplifier into a saturation state to create one of two stable states in which one of the second and the third beams is an enhanced beam and the other beam is a diminishing beam; at least one tapping device for tapping output signal from one of the first and the second optical paths, and at least one coupling device for coupling input signal into one of the

Abstract: An optical device guides propagating light to exit from a desired side surface of a substrate while maintaining sufficient power within a limited size of the substrate and which facilitates adjustment of a mount position of a light-receiving element by increasing allowable tolerance of the mount position of the light-receiving element. The optical device has a substrate, a light propagating direction path formed in the substrate, and a reflection groove formed in an output-side of said light propagating direction path in the substrate. A side wall of the reflection groove is formed to become a convex reflection surface in relation to light which enters from the light propagating direction path, and the light output from the light propagating direction path undergoes total reflection on a side wall forming the reflection surface and lets the reflected light exit from a predetermined side surface of the substrate while enlarging an image.

Abstract: Method for manufacturing of an optical fiber with a decoupling interface for scattered light to monitor the power of light guided through the optical fiber, where the optical fiber has a core having a first refractive index and a cladding surrounding the core, the cladding having a second refractive index smaller than the first refractive index, and where a portion of the optical fiber is substantially straightly aligned in the region of the decoupling interface, in which method the optical fiber is electro-thermally treated at an intermediate position within the substantially straightly aligned portion such that a partial mixture of core material and cladding material and, thereby, formation of scattering centers occurs in an interface region between the core and said the cladding, thereby forming the decoupling interface for scattered light from the modified intermediate position.

Abstract: An integrated device of the present invention comprises free-space optics, a bi-directional multiplexor/de-multiplexor, a diffractive light modulator, a beam splitter, an optical performance monitor, and a controller. The free-space optics collimate, transform and image optical signals including a range of component wavelength signals. The bi-directional multiplexor/de-multiplexor de-multiplexes a wavelength division multiplexed signal into the component wavelength signals and multiplexes equalized component wavelength signals into an equalized wavelength division multiplexed signal. The diffractive light modulator selectively equalizes each component wavelength signal. The beam splitter is optically coupled in free-space to the diffractive light modulator for receiving the equalized component wavelength signals and re-directing a representative portion of each of the equalized component wavelength signals.

Abstract: A polarization-maintaining optical fiber component which suppresses coupling of propagating light to a high-order mode at the optical coupling section of the polarization-maintaining optical fiber component, caused by different refractive indexes between the stress applying sections and the cladding, thus reducing excess loss, is constructed by using a polarization-maintaining optical fiber having stress applying sections arranged symmetrically to each other with respect to a core in a cladding surrounding the core, wherein the largest one of those concentric circles of the core or the said cladding which do not reach the stress applying sections and do not include the stress applying sections within has a diameter of 20 ?m or greater.

Abstract: In a device of the present invention for allowing signal light to enter a light guide body using an optical fiber, a light guide body, which is constituted by dispersing particles for scattering the signal light in an optical medium, is selected as a light guide path which requires an area where a light diffusing function is performed just after incidence of the signal light. An optical connecting material intervenes between one end of the optical fiber from which the signal light is output and opposed one end surface of a particle dispersing light guide body and a desired diffusing function is obtained.

Abstract: An optical power monitor comprises: an array waveguide grating comprising first and second optical interaction regions between which an input optical signal propagates from a first position on a first side of the first optical interaction region to a second position on a second side of the second optical interaction region, a correspondence between said first and second positions depending upon a wavelength of the optical signal, there being a plurality of array waveguides coupled between a second side of the first optical interaction region and a first side of the second optical interaction region, and a plurality of output waveguides coupled at one end to the second side of the second optical interaction region for outputting different wavelength channel outputs from the second optical interaction region; and detector for detecting said different wavelength channel outputs at the other ends of the output waveguides: wherein the plurality of output waveguides includes at least two output waveguides for at le

Abstract: A microchip may include an optical clocking system. The optical clocking system may include a ring resonator which multiplies the frequency of light pulses from a light source for use as optical clocking signals and distribution waveguides to distribute the optical clocking signals to different regions of the microchip.

Abstract: In a planar-waveguide-type optical circuit 1, a reflection filter 4 is placed inside an oblique groove 3 formed to traverse optical waveguides 2n. Reflected light from the reflection filter 4 is detected by photodetectors 61n of a photodetector array 6, and thereby light intensity of signal light is monitored. A glass substrate made of glass material having a refractive index substantially identical to that of a core 20 of the optical waveguide 2n and filter fixing resin 5 fixing the reflection filter 4 is used for a substrate 10 of the optical circuit 1 constituting part of the groove 3. This inhibits reflection of light in various regions of the groove 3, thereby reducing generation of extra scattered light inside the groove 3 and its confinement. An optical waveguide module capable of enhancing monitoring characteristics of the signal light is thus realized.

Abstract: An apparatus and method of attenuating and/or conditioning optical energy for an optical transmitter, receiver or transceiver module is disclosed. An apparatus for attenuating the optical output of an optoelectronic connector including: a mounting surface; an array of optoelectronic devices having at least a first end; an array of optical elements having at least a first end; the first end of the array of optical elements optically aligned with the first end of the array of optoelectronic devices; an optical path extending from the first end of the array of optoelectronic devices and ending at a second end of the array of optical elements; and an attenuator in the optical path for attenuating the optical energy emitted from the array of optoelectronic devices. Alternatively, a conditioner may be adapted in the optical path for conditioning the optical energy emitted from the array of optoelectronic devices.

Abstract: A single channel optical interconnect for a fiber optic system includes a penetrator made of optically transmissive material and configured for insertion along the length of a plastic optical fiber for transferring light between the optical fiber and an optoelectronic device. A multiple channel optical interconnect uses a linear array of optoelectronic devices and corresponding optically transmissive penetrators. The penetrators may be pyramidal or conical bodies made of plastic or glass that are positioned above corresponding vertical cavity surface emitting lasers (VCSELs). The penetrators may also be etched directly into the substrates of bottom emitting VCSELs. The penetrators may have specially tailored side wall angles, or coatings, to facilitate coupling into the optical fibers and minimize back reflections into the VCSELs.

Abstract: A tap-off capable of easily extending a hybrid fiber coaxial network without complicated cable handling and signal disruptions. The tap-off comprises a primary distributor connected to a directional coupler. Additional distributors are divergently connected to the primary distributor and include terminal distributors. Bridges are divergently connected to the terminal distributors, and an intermediate distributor is connected between the directional coupler and the primary distributor. The tap-off also has at least one extension port and at least one intermediate cable connecting the extension port with the intermediate distributor. Each bridge is connected to a drop cable for providing a signal to a subscriber. The intermediate distributor distributes the signal to the primary distributor and to the extension port. The tap-off further comprises an additional extension tap-off, which includes an input port connected to the extension port, distributors, and bridges.

Abstract: A tunable polarization dependent loss element is formed of a fiber including a highly tilted optical grating. The grating is formed at an angle of approximately 45° so as to preferentially scatter one polarization state out of the fiber core while allowing the remaining, orthogonal polarization to propagate unimpeded. By twisting the ends of the fiber grating structure, the orientation of the grating with respect to the fiber optical axis will be changed, modifying the amount of optical signal existing in each polarization state. In one embodiment, both ends may be rotated in the same direction through the same angular displacement, resulting in merely rotating the principle states of polarization in the fiber. Alternatively, the ends of the grating may be rotated (twisted) in opposite directions so as to couple all of the light signal into a single polarization state, reducing the amount of polarization dependent loss to essentially zero.

Abstract: An optical fiber array block includes at least one optical waveguide having an optical fiber zone, and an optical device. An optical signal leakage window is formed at the optical waveguide, and the optical device corresponds to the optical signal leakage window. If the optical signal leakage window is formed at an optical fiber comprising a core and a clad layer, the clad layer is partially removed or is partially connected to the core by means of an ion implantation technique.

Abstract: A system and method directed to an integrated fiber optic splitter assembly having at least two fused splitters disposed in a common substrate. An integrated optical splitter assembly includes a plurality of input fibers, a plurality of output fibers, and a plurality of splitters disposed on a single substrate to either split or couple optical signals between the input and output optical fibers.

Abstract: An improved fiber optic tap monitor has characteristics that are flatter over the wavelength range of interest. The polarization dependence of the characteristics of the tap monitor is reduced, and the package for the tap monitor is smaller. The tap monitor reduces the amount of light reflected back to the source. The tap monitor is also assembled in a manner to improve temperature stability, so that its characteristics over a range of temperatures are more nearly constant.

Abstract: An integrated, optically amplified receiver includes an optically pumped optical preamplifier for receiving, generally, wavelength division multiplexed optical communication signal over an optical communications line. A PIN photodetector receives the optical communication signal as a filtered demultiplexed signal from the optical preamplifier and converts the optical communication signal into an electrical communication signal. An amplifier circuit amplifies the electrical communication signal for digital retiming or demodulation. A housing or printed circuit card assembly contains the optical preamplifier, filter or demultiplexer, PIN photo detector and amplifier circuit as an integrated receiver unit.

Abstract: A basic reflector arrangement has first and second power splitters. Each power splitter has first to fourth ports where the first port of the first power splitter is coupled to a remote signal source for receiving signals therefrom and providing feedback signals thereto. Signals received at each of the first and fourth ports of each power splitter are combined and split into first and second portions for transmission via the second and third ports, respectively, and signals received at the second and third ports are combined and split into first and second portions for transmission via the first and fourth ports, respectively. The second port of the second power splitter is coupled to provide an output signal from the reflector arrangement, and the first, third, and fourth ports thereof are coupled to the second, third, and fourth ports, respectively, of the first power splitter.

Abstract: Transmission signal light emitted from a light emitting element is coupled to an optical waveguide and guided into a transmission line. A light monitor a portion of leakage light, which is used for control of optical output of the light emitting element. The optical semiconductor module is covered with transparent resin that is closely matched to the refractive index of a clad layer covering the optical waveguide. The light leaked to the inside of the clad layer is not reflected at a top surface of the clad layer and is received at a light receiving surface of the light monitor.

Abstract: An optical network, in the form of a 1×2N splitter, includes a series of interconnected distribution devices of varying size. Each distribution device may be an H-tree distribution device having an input waveguide and four output waveguides that provide in-phase, equal intensity copies of a signal received on the input waveguide. The network may include a primary H-tree distribution device and a plurality of secondary H-tree distribution devices each of a smaller size than the primary H-tree distribution device. Individual H-tree distribution devices may have a first stage Y-branch and a second stage Y-branch each of different radii of curvature. Further still, progressively smaller radius of curvature Y-branches may be used to form the 1×2N splitter, where N may be an even or odd integer.

Abstract: An optical power splitter is provided that can stably operate even when there is a mode mismatch between an input optical signal and the optical power splitter. The optical power splitter of the present invention includes a semiconductor substrate, an optical waveguide stacked on the semiconductor substrate, and a clad surrounding the optical waveguide.

Abstract: Optical systems are provided. A representative optical system includes an optical transceiver with an optical source and an optical receiver. The system also includes an optical bus. At least one of the optical source and the optical receiver is optically coupled to an intermediate portion of the optical bus. The optical source provides optical signals for propagation by the optical bus, and the optical receiver detects optical signals differentially. Methods and other systems also are provided.

Abstract: An optical package substrate and a molding method therefor which provide for easy production, easy mounting of optical elements such as photodiodes and lasers, good functionality, productivity and economy, and an optical device incorporating the package substrate. On the surface of an optical package substrate, a guide groove used for the positioning of an optical fiber and a tapered face adjoining the guide groove are provided, the tapered face being formed to have a predetermined angle. A mirror for reflecting light is formed on the tapered face. An optical fiber is affixed in the guide groove. A surface reception type photodiode, which is placed in a position for receiving light deflected by the mirror, is mounted above the tapered face. By providing a positioning marker for a light receiving element on the optical package substrate, it becomes particularly easy to mount the surface reception type photodiode through passive alignment.

Abstract: An optical pump device including a pump source optically connected to an optical divider including one input channel and n output channels. The input channel is configured to receive a pump wave derived from the source and the n output channels are configured to output n pump waves, where n is an integer greater than 1. The pump device can be used in an optical amplification device. The device has applications in all domains in which several optical pumps are necessary, and more particularly in the domain of optical telecommunications, and for example for optical amplifiers.

Abstract: An optical cross-connect switch is disclosed for switching optical communication signals between any of a plurality of input optical channels and any of a plurality of output optical channels. The switch comprises a first pattern projector configured to project one or more first control signal radiation patterns and a plurality of output encoders. Each output encoder is associated with one of the plurality of output optical channels. Each output encoder is positioned, relative to its associated output optical channel and the first pattern projector, to receive the first control signal radiation patterns and to detect at least a portion of one or more corresponding output Moiré interference patterns produced by the control signal radiation patterns. Each output encoder is configured to generate a corresponding output control signal indicative of an intensity of detected output Moiré interference patterns.

Abstract: Devices and techniques for monitoring spectrum of light. For example, a fiber spectral monitoring device and associated technique are described for monitoring spectral information in light based on an interferometer design.

Abstract: A branching unit is provided for interconnecting at least three undersea optical transmission cables. The branching unit includes first, second and third ports for receiving first, second and third undersea optical transmission cables, respectively. The first and second cables each include an electrical power conductor and a plurality of first optical fibers. The third cable is electrically unpowered and includes at least one drop optical fiber and at least one add optical fiber. An electrical power conductor segment is provided for electrically coupling the conductor in the first cable received in the first port to the conductor in the second cable received in the second port. A first optical fiber segment optically couples a first of the plurality of first optical fibers in one of the first or second cables to the drop optical fiber of the third cable.

Abstract: The present invention aims at providing a control method and a control apparatus for controlling the operation setting of an optical device with high accuracy, so as to reliably obtain characteristics according to a desired relationship to be set corresponding to a signal light, immediately after the control start.

Abstract: A system for processing an optical signal into a plurality of optical output signals includes a laser for generating an optical signal along an optical signal path. An optical splitter receives the optical signal and includes an input optical fiber and a stepped, optical splitter circuit formed from a plurality of laser ion doped optical waveguides branching into a plurality of output optical signals. An optical pump source pumps an optical pump signal through the stepped, optical splitter circuit and excites the erbium to distribute gain throughout the optical splitter.

Abstract: To provide an optical device and method for manufacturing the same that allow a reduction in size and the easy fabrication of an optical splitter or an optical coupler with which the branching ratio or the coupling ratio can be dynamically changed after device production. An optical device is provided with a photonic crystal having a periodic refractive index distribution due to a periodic arrangement of a plurality of materials of different refractive indices, an input-side optical waveguide for making light incident on the photonic crystal, and an output-side optical waveguide for emitting light from the photonic crystal, and further includes an external drive portion for changing a relative position of the photonic crystal and at least one of the input-side optical waveguide and the output-side optical waveguide, thereby allowing a small, high-performance optical device to be achieved.