Abstract: The present invention provides a small optical waveguide structure capable of converting the spot size of light, and capable of reducing the conversion loss when compared under the condition of the same waveguide length and performing an optical conversion with high efficiency. An optical waveguide structure (100) includes a base waveguide (110) including a taper section (111) whose width becomes continuously narrower from one side toward another side, and a narrow-width section (112) that is consecutively connected to a narrow-width side of the taper section (111) and extends toward the another side.

Abstract: An all-fiber combiner device is described for combining multiple high power inputs, such as high power laser inputs. The device includes a first tapered fiber section made from fibers that allow for efficient size reduction of the optical signals. The output of the first tapered fiber section may then be coupled to a multimode output fiber for delivery of the combined power beam. Alternately, the first tapered section can be coupled to a second, multimode, tapered section, which provides further size reduction of the core for splicing into a final output fiber, while adding cladding to the main fiber.

Abstract: A solid state waveguide coupler is provided including a first coupler end disposed on a solid state material substrate for connection to a first solid state waveguide located on the substrate and a second coupler end disposed on the substrate for connection to a second waveguide located on the substrate. A coupling span, comprising a waveguide material layer on the substrate, is disposed between the first and second coupler ends and tapers between a height of the first waveguide and a height of the second waveguide, tapers between a width of the first waveguide and a width of the second waveguide, and includes curved sidewalls along at least a portion of the tapered coupling span. In a method for fabricating the waveguide coupler, material is isotropically removed from a waveguide material layer on the substrate to produce tapered surfaces between the first waveguide and the second waveguide.

Abstract: Provided are optical coupling devices and silicon photonics chips having the same. the optical coupling device may include a lower layer having a first region and a second region, a first core layer disposed on the lower layer, the first core layer including first and second waveguides disposed on the first and second regions, respectively, a clad layer covering the first waveguide, and a second core layer interposed between the clad layer and the lower layer to cover the second waveguide. The second waveguide has a width decreasing with increasing distance from the first region and a vertical thickness greater than that of the first waveguide.

Abstract: Provided is a core which reduces optic splice loss between discontinuous optical waveguides.

Abstract: An analytical device including an optically opaque cladding, a sequencing layer including a substrate disposed below the cladding, and a waveguide assembly for receiving optical illumination and introducing illumination into the device. The illumination may be received from a top, a side edge, and a bottom of the device. The waveguide assembly may include a nanoscale aperture disposed in the substrate and extending through the cladding. The aperture defines a reaction cell for receiving a set of reactants. In various aspects, the device includes a sensor element and the illumination pathway is through the sensor element. Waveguides and illumination devices, such as plasmonic illumination devices, are also disclosed. Methods for forming and operating the devices are also disclosed.

Abstract: An optical semiconductor device in which light having a wavelength of 1.25 ?m or greater is waveguided, includes: a first waveguide of embedded type that includes a semiconductor and is lattice-matched with InP, the first waveguide having a region having a first constant width equal to or greater than 1.50 ?m and a first region narrower than the region; and a second waveguide of embedded type that includes another semiconductor having a refractive index different from that of the first waveguide, the second waveguide having a region having a second constant width smaller than 1.50 ?m and a second region wider than said region. The first waveguide and the second waveguide are joined at an intermediate waveguide portion. The intermediate waveguide portion includes the first region and the second region and a joining plane on which the first region and the second region are joined. The joining plane has a width equal to or smaller than 1.35 ?m.

Abstract: A chiral optical fiber polarizer is provided that is capable of being fabricated in-line along a conventional polarization maintaining fiber having external structural element(s), positioned between two optical fiber portions, and includes a modified central portion with altered fiber cladding interface elements on each side thereof. The modified central portion includes at least one diameter reduced sub-section that allows a light signal to propagate simultaneously in the core and in at least one external structure element, and at least one diameter expanded sub-section that allows the light signal to propagate substantially in the core, where the modified central portion is configured to be operable to serve as a polarizer for light signals with linear polarization components.

Abstract: Apparatus and methods that compensate for the thermally-induced drift of the resonance frequency of a closed-loop resonator include, in an exemplary embodiment, a waveguide-based Mach-Zehnder interferometer (MZI) and an overcoupled, waveguide-based microring resonator. The temperature-induced red-shifting ring resonance can be balanced by a spectral blueshift with temperature of the MZI. To stabilize the resonance of the ring at a given wavelength, the change in optical path lengths with temperature of the ring and the MZI should be equal and opposite. The interplay of nonlinear change in phase of ring resonator with temperature and linear change in phase of MZI with temperature, along with matching the period of this phase change, gives rise to perfect oscillation in the combined system resonance with temperature.

Abstract: An optical fiber mode coupling device, capable of being readily connected to a conventional optical fiber with a high degree of ruggedness, is provided. The inventive mode coupling device only allows transmission of at least one supported fiber mode therethrough, and is preferably configured to maximize the coupling, of at least one desired fiber mode, to the at least one supported fiber mode. Advantageously, the inventive mode coupling device is capable of performing the functions of a mode filter for the signal entering its first end, or serving as a mode conditioner for the signal entering its opposite second end.

Abstract: The present invention provides a method for producing a Mach-Zehnder filtering device. The method includes the following steps: (a) providing an optical fiber having a jacket and a core containing rare earth element dopants; (b) stripping the jacket of a segment of the optical fiber; and (c) performing a fused-tapering to the stripped segment of the optical fiber to form a first and a second necks simultaneously, wherein the core exists in both the first and the second necks to form a Mach-Zehnder interferometer.

Abstract: Methods, systems, and products illuminate display devices. An image is injected into a tapered portion of a waveguide. The tapered portion reflects the image to create total internal reflectance of the image within the waveguide. A frustrator withdraws a frustrated image from the waveguide, and the frustrated image is displayed to a viewer.

Abstract: The present invention relates to a waveguide coupling device with properties of forward coupling and backward coupling as well as a manufacturing method thereof, the waveguide coupling device comprises: a substrate, at least one inverted taper coupling structure, an intermediate layer, and at least one three-dimensional taper coupling structure. Wherein one end of the three-dimensional taper coupling structure is adopted for connecting to an external optical fiber, so as to couple the optical wave propagating in the optical fiber; Moreover, by way of the specific coupling sequence of (three-dimensional taper coupling structure)-(intermediate layer)-(inverted taper coupling structure), the optical wave may be efficiently coupled into, be confined in, and ultimately propagates in the inverted taper coupling structure connecting to waveguide devices.

Abstract: An optical fiber coupler array capable of providing multiple low loss, high coupling coefficient interfaces between a predetermined number of low numerical aperture optical fibers and an optical waveguide device with at least a corresponding number of waveguide interfaces. The novel coupler array includes a plurality of coupler inner cores and a plurality of corresponding coupler outer cores, within a medium surrounding each outer core, and also includes a first end for interfacing with optical fibers and a second end for interfacing with a plurality of waveguide interfaces of an optical waveguide device. The sizes of the inner and outer cores are gradually reduced from the first end to the second end in accordance with at least one predetermined reduction profile, such that the coupler array comprises a plurality of low numerical aperture waveguides at the first end, and a plurality of high numerical aperture waveguides at the second end.

Abstract: Provided are an optical waveguide for a touch panel which has high light-gathering power on a light-emitting side and which may materialize a touch panel having excellent position detection performance, and a touch panel using the optical waveguide. The optical waveguide for a touch panel includes: cores; and an over cladding layer covers the cores, the cores including light-emitting cores each formed as a lens portion having a shape in plan view including a tapered portion whose width gradually increases toward an end surface on the light-emitting side and an elliptical arc portion which bulges outwardly a tip side of the tapered portion having the gradually-increasing width so as to be in a shape of an elliptical arc, the elliptical arc portion having a major axis direction aligned in a longitudinal direction of the tapered portion.

Abstract: A section of active optical fiber (11) which comprises an active core (1), an inner cladding layer (2) and an outer cladding layer (3). The diameter of said core 1) and the thickness of said inner cladding (2) change gradually along the length of said section of active optical fiber (11). This forms tapered longitudinal profile enabling a continuous mode conversion process along the length of the section of fiber (11). The method for fabricating a section of tapered active optical fiber comprises the steps of fabricating a preform for drawing active optical fiber from said preform, installing said preform into a drawing tower, drawing optical fiber in said drawing tower and altering at least one of the two parameters including the take-off preform speed and the take-up fiber speed during drawing of the optical fiber.

Abstract: A multi-core optical fiber which has a plurality of core portions arranged separately from one another in a cross-section perpendicular to a longitudinal direction, and a cladding portion located around the core portions, the multi-core optical fiber comprises a cylindrical portion of which diameter is even, and a reverse-tapered portion gradually expanding toward at least one edge in the longitudinal direction, wherein a gap between each adjacent ones of the core portions in the reverse-tapered portion is greater than that in the cylindrical portion.

Abstract: An optical fiber structure (10) includes an optical fiber (11a), and a block-like chip (12) joined to the optical fiber (11a). The block-like chip (12) is tapered toward its fiber-joined end.

Abstract: A light guide of the tapered-waveguide type includes an input slab for expanding a projected image between an input end and an output end, and an output slab arranged to receive rays from the said output end, and to emit them at a point on its face that corresponds to the angle at which the ray is received. The input slab and output waveguide are matched so that all rays injected into the input end undergo the same number of reflections before leaving the output surface. With the invention, the input slab is itself tapered slightly towards the output waveguide. This means that input and output waveguides can be made the same length, in the direction of ray travel, and can therefore be folded over each other with no wasted space.

Abstract: The present invention provides an optical branching device and an optical communication system which are easy to connect with optical fibers. In the optical branching device, when light emitted from an optical fiber in a front stage is incident on an entrance port of a multicore optical fiber, the light propagates through a first core and then is distributed from the first core to four second cores by core-to-core crosstalk between the first and second cores. The light beams distributed to the four second cores propagate through the respective cores and are emitted to four optical waveguides optically coupled core-to-core thereto within a fan-out part at exit ports.

Abstract: The present invention relates to a 3-D waveguide coupling device capable of two-step coupling and a manufacture method thereof, the 3-D waveguide coupling device comprises: a first substrate, at least one waveguide layer, at least one assisting grating, at least one coupling material layer, and at least one 3-D tapered structure layer, wherein 3-D waveguide coupling device is able to couple the light into the waveguide layer by way of two-step coupling through the 3-D tapered structure layer, the coupling material layer and the assisting grating. Moreover, the light can also be coupled out from the waveguide layer through the assisting grating, the coupling layer, and the 3-D tapered structure. The manufacture method is adapted to fabricate the 3-D waveguide coupling device capable of two-step coupling via the present semiconductor process technology without increasing any other new equipment.

Abstract: An opto-electric hybrid module capable of shortening the distance between a light-emitting section or a light-receiving section of a semiconductor chip and a reflecting surface formed in a core to reduce optical losses between an opto-electric conversion substrate section and an optical waveguide section, and a method of manufacturing the same. A recessed portion (3a) is formed in a surface of an over cladding layer (3) of the optical waveguide section (W1). At least part of the light-emitting section (7a) or the light-receiving section of the semiconductor chip (7) for opto-electric conversion and at least part of a loop portion (8a) of a bonding wire (8) in the opto-electric conversion substrate section (E1) are positioned within the recessed portion (3a). This brings the light-emitting section (7a) or the light-receiving section of the semiconductor chip (7) and the reflecting surface (2a) formed in the core (2) closer to each other.

Abstract: An apparatus and method for providing image acquisition and/or image display in a limited region of interest (ROI). The apparatus comprises a micro-electro-mechanical system (MEMS), preferably integrating a light source, a cantilever, a lens, an actuator, a light detector, and a position sensor. The light source provides light for illuminating the ROI, displaying an image, providing a therapy, and/or performing other functions. The cantilever comprises a resin waveguide with a fixed end attached to a substrate that supports many or all other components. A free end of the cantilever is released from the substrate during fabrication and includes the lens. The actuator scans the free end in orthogonal directions to illuminate the ROI or display an image. The position sensors detect the position of the free end for control. The light detector receives light backscattered from the ROI separate from, or at the fixed end of the cantilever.

Abstract: A waveguide coupler includes a first waveguide and a second waveguide. The waveguide coupler also includes a connecting waveguide disposed between the first waveguide and the second waveguide. The connecting waveguide includes a first material having a first index of refraction and a second material having a second index of refraction higher than the first index of refraction.

Abstract: In one exemplary embodiment, a transmission line geometry or structure may readily be realized as periodic printed coupled/uncoupled microstrip lines on dielectric and/or suitable biased ferromagnetic substrates. An example of a transmission line geometry or structure may be adapted to emulate extraordinary propagation modes within bulk periodic assemblies of anisotropic dielectric and magnetic materials. For instance, wave propagation in anisotropic media may be emulated by using a pair of coupled transmission lines (30, 32) having a specially designed geometry, thereby enabling mold wave dispersion in a microwave or optical guided wave structure. Degenerate band edge resonances, frozen modes, other extraordinary modes, and other unique electromagnetic properties such as negative refraction index may be realized using unique geometrical arrangements that may, for example, be easily manufactured using contemporary RF or photonics/solid state technology.

Abstract: Optical devices for guiding illumination are provided each having a body of optical material with staircase or acutely angled ramp structures on its top surface for distributing light inputted from one end of the device from the front exit faces of such structures along certain angular orientations, while at least a substantial portion of the light is totally internally reflected within the body until distributed from such front exit faces. Optical devices are also provided each have a body of optical material having a bottom surface with acutely angled ramp structures and falling structures which alternate with each other, such that light is totally internally reflected within the device until reflected by such ramp structures along the bottom surface to exit the top surface of the device or transmitted through the ramp structures to an adjacent falling structure back into the device.

Abstract: An optical coupling assembly for coupling light from an optical fiber including an angled tip into a planar waveguide via a waveguide coupling element is provided. In one embodiment, the optical fiber extends along the planar waveguide with the angled tip positioned such that light propagating in the optical fiber is coupled by the waveguide coupling element to propagate in the planar waveguide in counter propagation with respect to a fiber propagation direction. In another embodiment, the optical fiber includes a tapered peripheral portion tapering toward the angled tip and is disposed over the planar waveguide with the tapered peripheral portion extending therealong such that light propagating in the optical fiber is coupled to propagate in the planar waveguide with either forward or counter propagation. Embodiments of the present invention may be part of various photonic integrated circuits and may be manufactured more easily than known optical coupling assemblies.

Abstract: In an optical waveguide 10 with a light emitting device to be used in the present invention, branched points 16 are sequentially provided in a guiding light direction 17 of a main path 14 and the width of the main path 14 becomes narrower as the main path 14 moves away from a light emitting device 11. The optical waveguide 10 having this structure can reduce a width W1 because there are no portions that correspond spaces (cladding layers) among adjacent branched paths 15. Moreover, the optical waveguide 10 has an excellent optical transmission efficiency, resulting in high intensity of light emitted. Uniformity of the light emitted is equal or more than a conventional optical waveguide 60 with a light emitting device.

Abstract: An optical semiconductor device, including a first optical waveguide with a first width, a second optical waveguide with a second width narrower than the first width with a bending region, and a third optical waveguide with a third width wider than the second width and coupled to the second optical waveguide.

Abstract: A waveguide stub is connected to a pillar-type square-lattice photonic crystal waveguide. Within the waveguide stub, the diameter of a defect is made larger than that of the original photonic crystal waveguide thereby reducing the group velocity of a guided light. The original waveguide and the waveguide stub are smoothly connected via a taper waveguide. Because of low group velocity of light in the waveguide stub, free spectral range (FSR) decreases thereby allowing the size of the waveguide stub to be reduced.

Abstract: A system for combining multiple fiber amplifiers, or multiple fiber amplifiers. The system includes a fiber combiner with multiple cores for connecting with the multiple fiber amplifiers and for combining the beams of the fiber amplifiers into a single beam. The fiber amplifiers are aligned, tapered, and stretched. A method for combining fiber amplifiers includes emitting a beam from a tapered fiber combiner and transmitting and coupling a portion of the emitted beam back into the fiber combiner via a feedback fiber. The transmission and coupling of the feedback fiber includes mixing the feedback fiber with the output of an auxiliary laser and boosting the feedback fiber by a pre-amplifier. The feedback fiber is split into a plurality of beams by a fiber splitter. The beams are fed into an array of fiber amplifiers and combined with output of the individual fiber amplifiers to form the tapered fiber combiner.

Abstract: Embodiments of optical collimators are disclosed. For example, one disclosed embodiment comprises an optical waveguide having a first end, a second end opposing the first end, a viewing surface extending at least partially between the first end and the second end, and a back surface opposing the viewing surface. The viewing surface comprises a first critical angle of internal reflection, and the back surface is configured to be reflective at the first critical angle of internal reflection. Further, a collimating end reflector comprising a faceted lens structure having a plurality of facets is disposed at the second end of the optical waveguide.

Abstract: Systems and methods provide for illuminating a subject using a light pipe that transmits light from a source. A method includes providing a light pipe, the light pipe defining an inner lumen through which the image sensor views the subject; providing a light source in alignment with a proximal portion of the light pipe; and using the light source, projecting a light into the light pipe and through the light pipe, the light pipe including a distal portion for providing a high-angle bright field illumination pattern on the subject with a first portion of the light and for reflecting a second portion of the light for providing a low-angle dark field illumination pattern on the subject.

Abstract: A light guide for endoscopes is constituted by a plurality of multimode optical fibers, of which at least a portion is bundled. The light guide propagates illuminating light beam that enters from a first end facet thereof to a second end facet thereof, to emit the illuminating light beam onto a portion to be observed. The light guide includes: a light input portion formed by the bundled plurality of multimode optical fibers; and a light output portion formed by the bundled plurality of multimode optical fibers. At least one of the light input portion and the light output portion is shaped in a tapered shape, while the number of multimode optical fibers at the light input portion and the light output portion are the same as that at other portions of the light guide.

Abstract: An optical coupler, the optical coupler being usable with a first optical fibre and a second optical fibre. The second optical fibre defines a second fibre coupling section and a second fibre transmitting section extending from the second fibre coupling section. The second fibre coupling section defines a radially outwardmost peripheral surface, the radially outwardmost peripheral surface defining a peripheral surface coupling portion. The optical coupler includes a coupler first end section and a substantially opposed coupler second end section, the coupler first end section defining a first coupling surface. The optical coupler defines a second coupling surface extending along the coupler first and second end sections. The first coupling surface is optically couplable with the first optical fibre and the second coupling surface is positionable so as to extend substantially parallel to the peripheral surface coupling portion and to be optically coupled with the peripheral surface coupling portion.

Abstract: Disclosed are optical assemblies such as field-installable connectors having a laser-shaped optical fiber along with methods for laser-shaping the optical fiber. The field-installable connector includes a ferrule having front and rear opposed faces and at least one fiber bore defined longitudinally therethrough, a stub optical fiber having a distal end with a laser-shaped end face is disposed within the at least one fiber bore of the ferrule and extends a predetermined distance beyond the rear face of the ferrule, and an alignment feature operable for aligning the stub optical fiber with the field optical fiber. One method of laser-shaping the optical fiber includes rotating the optical fiber and sweeping a beam of a laser across the optical fiber and then essentially stopping the rotation of the optical fiber and sweeping the beam through the optical fiber to cut the same with a tapered and angled end face.

Abstract: An opto-electric hybrid module capable of shortening the distance between a light-emitting section or a light-receiving section of a semiconductor chip and a reflecting surface formed in a core to reduce optical losses between an opto-electric conversion substrate section and an optical waveguide section, and a method of manufacturing the same. A recessed portion (3a) is formed in a surface of an over cladding layer (3) of the optical waveguide section (W1). At least part of the light-emitting section (7a) or the light-receiving section of the semiconductor chip (7) for opto-electric conversion and at least part of a loop portion (8a) of a bonding wire (8) in the opto-electric conversion substrate section (E1) are positioned within the recessed portion (3a). This brings the light-emitting section (7a) or the light-receiving section of the semiconductor chip (7) and the reflecting surface (2a) formed in the core (2) closer to each other.

Abstract: An apparatus that comprises an optical-mode-converter. The optical-mode-converter includes a optical waveguide including a segment directly located on a substrate and a cantilevered segment located over said substrate and separated from said substrate by a cavity, and, said cantilevered segment includes a core surrounded by a cladding. The optical-mode-converter also includes a dielectric material filling said cavity and contacting said cantilevered segment over said cavity, wherein said dielectric material has a refractive index that is less than a refractive index of said cladding and that is no more than about 20 percent less than said refractive index of said cladding.

Abstract: An optical fiber coupler array capable of providing multiple low loss, high coupling coefficient interfaces between a predetermined number of low numerical aperture optical fibers and an optical waveguide device with at least a corresponding number of waveguide interfaces. The novel coupler array includes a plurality of coupler inner cores and a plurality of corresponding coupler outer cores, within a medium surrounding each plural outer core, and also includes a first end for interfacing with plural optical fibers and a second end for interfacing with a plurality of waveguide interfaces of an optical waveguide device. The sizes of the inner and outer cores are gradually reduced from the first end to the second end in accordance with at least one predetermined reduction profile.

Abstract: An optical assembly comprising (10) an optical coupler (12) defining a coupler first end section (18), a substantially opposed coupler second end section (20) and a coupler intermediate section (22) therebetween; a coupler passageway (24) extending in the coupler intermediate section (22) and also through at least a portion of the coupler second end section (20) and defining a passageway second end aperture (30) leading into the coupler passageway (24); a coupler peripheral surface (26) extending peripherally to the coupler passageway (24) in the coupler intermediate section (22); and a coupler lateral aperture (28) extending between the coupler passageway (24) and the coupler peripheral surface (26) in the coupler intermediate section (22). A first end optical fibre (14) is optically coupled to the optical coupler (12) in the coupler first end section (18) for allowing propagation of light between the optical coupler (12) and the first end optical fibre (14).

Abstract: This document discusses, among other things, a connector for an optical imaging probe that includes one or more optical fibers communicating light along the catheter. The device may use multiple sections for simpler manufacturing and ease of assembly during a medical procedure. Light energy to and from a distal minimally-invasive portion of the probe is coupled by the connector to external diagnostic or analytical instrumentation through an external instrumentation lead. Certain examples provide a self-aligning two-section optical catheter with beveled ends, which is formed by separating an optical cable assembly. Techniques for improving light coupling include using a lens between instrumentation lead and probe portions. Techniques for improving the mechanical alignment of a multi-optical fiber catheter include using a stop or a guide.

Abstract: The present invention provides a passive optical splitter and a passive optical network system. The passive optical splitter includes at least two splitting single-mode waveguides, at least one combining single-mode waveguide, and at least one tapered waveguide, where one end of the tapered waveguide is coupled to the at least two splitting single-mode waveguides respectively, the other end of the tapered waveguide is coupled to the at least one combining single-mode waveguide, and a core layer of the tapered waveguide is made of a light-induced refractive index changeable material. When an optical signal is transmitted, light transmission is limited by increasing a refractive index difference between positions with different optical field intensity in the core layer, thus reducing a loss of optical signal leakage and improving uplink transmission efficiency.

Abstract: An optical hybrid circuit includes a multimode interference coupler; a first 2:2 optical coupler; a second 2:2 optical coupler; a third 2:2 optical coupler; and a phase controlling region. The first 2:2 optical coupler, the second 2:2 optical coupler, and the third 2:2 optical coupler are coupled to one of the pair of first output channels, the pair of second output channels, the pair of third output channels, and the pair of fourth output channels of the multimode interference coupler. The phase controlling region is provided in one or both of each pair of at least two pairs of output channels from among three pairs of output channels to which the first 2:2 optical coupler, the second 2:2 optical coupler, and the third 2:2 optical coupler are coupled, respectively.

Abstract: To provide a super luminescent light emitting diode comprising an optical waveguide structure which supplies particularly-high optical output. The super-luminescent light emitting diode includes: a first optical waveguide, of which one end is optically connected to one end of a multimode interference optical waveguide, and of which the other end forms a first light emitting edge; and a second optical waveguide, of which one end is optically connected to the other end of the multimode interference optical waveguide, and of which the other end forms a second light emitting edge. Each of the first and second optical waveguides has a width smaller than the width of the multimode interference optical waveguide.

Abstract: An optical system is disclosed. The optical system includes first and second waveguides, a first dispersive element, and a coupler. The first waveguide is configured to support a first mode and a second mode of an optical input signal. The second mode being of a higher order than the first mode. The second waveguide has an input and an output and is configured to receive a portion of the optical input signal. The first dispersive element is disposed along a length of one of the first or second waveguides. The first dispersive element including a waveguide segment configured to induce a frequency-dependent phase shift in one of the portions of the optical input signal. The coupler is configured to couple the portion of the optical input signal in the second waveguide and the portion optical input signal in the first waveguide into the first waveguide. The coupling excites the second mode of the first waveguide to create a multimode optical signal.

Abstract: An optical waveguide includes a substrate in the shape of a flat plate; lower clad that is disposed on the substrate; and a core that is disposed on the lower clad and transmits light. The optical waveguide includes a first optical waveguide and a second optical waveguide. The first optical waveguide includes a first core on the lower clad, and is disposed so as to extend along a direction in which the light travels to a first position. The second optical waveguide includes a second core on the lower clad, is disposed so as to extend along a direction in which the light travels to a second position, and has a lower relative refractive index difference than the first optical waveguide. The first optical waveguide and the second optical waveguide form, between the first position and the second position, a layer structure where the first core and the second core are disposed such that the first core is positioned a predetermined distance away from the second core in a direction perpendicular to the substrate.

Abstract: An annular side fire optical device for laterally redirecting electromagnetic radiation comprises a tapered section of silica, a conical section of silica adjoining the tapered section and an annular beveled end surface. The tapered section of silica has a diameter that increases with distance along a longitudinal axis in a direction toward a transmitting end. The conical section of silica comprises a wall of silica surrounding a conical bore. The conical bore has a diameter that increases with distance along the longitudinal axis in a direction toward the transmitting end. The annular beveled end surface is formed in the wall of silica at the transmitting end and is angled relative the longitudinal axis such that electromagnetic radiation propagating along the longitudinal axis through the conical section is reflected by the beveled end surface at an angle that is transverse to the longitudinal axis.

Abstract: Provided is an optical connector including: an SI-type light source side optical fiber which is disposed on the light source side and an SI-type light receiving side optical fiber which is disposed on the light receiving side. Both optical fibers are optically coupled to each other by disposing an end surface of the light source side optical fiber and an end surface of the light receiving side optical fiber so as to face each other. The light source side optical fiber and the receiving side optical fiber are attachable to and detachable from each other. The light source side optical fiber includes a taper portion in which the diameter of the core portion increases toward the end surface of the light source side optical fiber.

Abstract: A light switch is disclosed to turn on or off the light signal in a light channel by means of the response of piezoelectric material to the electric field of light in the light channel. The LIGHT TRIGGERED LIGHT SWITCH is a light switch that is actuated by light of sufficient power. Light of different frequencies may travel in a light channel together without hindering each other, as long as the channel is the right size for both frequencies of light. The light that actuates the switch may be a different frequency than the light signal that is switched on or off. Fiber optic communication channels are among the channels that these switches may be used for.

Abstract: An optical coupler is provided. It has a bundle of multimode fibers with a few-mode fiber in its centre. Such bundle is fused at one end which is the output end for the signal that is transmitted by the few-mode fiber. To make the coupler, this output end of the bundle is aligned and spliced with a large area core double clad fiber while preserving the modal content of the feed-through. A method for making such optical coupler is also provided. It includes the steps of bundling a central few-mode fiber with a plurality of multimode fibers and then fusing one end of such bundle and aligning it and splicing with a large core double clad fiber, while preserving fundamental mode transmission from one to the other.