Abstract: An optical fiber coupler is formed of a section of optical fiber that is positioned between a conventional input fiber (for example, a single mode fiber) or waveguide and a coiled optical fiber device. The adiabatic coupler is coiled (or, at least, curved) to assist in transforming a conventional fundamental mode optical signal propagating along the longitudinal axis of the input fiber to an optical signal that is shifted into a peripheral region of the coiled optical fiber. Moreover, the pitch of an inventive coiled optical fiber coupler can be controlled to assist in the adiabatic transformation process.

Abstract: An optical waveguide of the invention includes a core that is a waveguide through which light propagates; and a cladding that surrounds the core. The core has a plate shape and includes a wide core base part onto which the light is incident, a taper part that is connected to the core base part and of which a width is gradually tapered along a propagation direction, and a narrow front end core part that is connected to the taper part and that extends along the propagation direction.

Abstract: In an optical coupling device, a main waveguide have a linearly extending portion and a tapered portion formed on a first clad layer. The waveguide has a width which is gradually reduced towards an incident side of the light wave. Auxiliary waveguides are formed on the both sides of the main waveguide, wherein each of the auxiliary waveguides has first and second tapered portions having widths which are gradually reduced toward both sides. A second clad layer is so formed as to cover the main and auxiliary waveguides and first clad layer, wherein the first clad layer guides the light wave introduced into the first clad layer or the second clad layer and gradually converge the light wave towards the main waveguide.

Abstract: Various exemplary embodiments relate to an optical waveguide coupler including: a first optical waveguide including a first area and a tapered area having a tapered width; a second optical waveguide including a first area and a tapered area having a tapered width; wherein the first area of the of the second optical waveguide overlaps the tapered area of the first optical wave guide, and wherein the tapered area of the second optical waveguide overlaps the first area of the first optical waveguide.

Abstract: A tapered waveguide optical mode transformer (20) includes a tapered core formed on a planar substrate structure (16). To vertically taper the core (21), steps (22) are etched into the top surface of the core. The steps have depths and lengths along the optical axis of tapered waveguide that are selected to transform the optical mode characteristics of a desired optical fiber to the optical mode characteristics of a desired planar waveguide. The core can also be tapered horizontally to form a 2-D tapered waveguide. The tapered waveguide can be integrally included in planar lightwave circuits (PLCs) to reduce light coupling losses between optical fibers and the PLC waveguides.

Abstract: An optical system including a plurality of fibers each providing a fiber beam and at least one tapered fiber bundle. The tapered fiber bundle includes a plurality of input end fibers, a plurality of output end fibers and a center bundle portion, where each input end fiber is coupled to a separate one of the fibers, and where the bundle portion combines all of the fiber beams received by the input end fibers into a single combined beam and each output end fiber is capable of receiving the combined beam separately from the other output end fibers. The optical system also includes a plurality of optical output channels where each optical output channel is coupled to a separate one of the output end fibers.

Abstract: A fiber laser amplifier system including a plurality of master oscillators each generating a signal beam at a different wavelength. A splitter for each master oscillator splits the signal beam into a plurality of fiber beams to be separately amplified. A separate tapered fiber bundle receives the amplified beam for each master oscillator, where each tapered fiber bundle includes a plurality of input end fibers, a plurality of output end fibers and a center bundle portion, where each input end fiber is coupled to a separate one of the fiber amplifiers, where the bundle portion combines all of the fiber beams received by the input end fibers into a single combined beam and each output end fiber is capable of receiving the combined beam separately from the other output end fibers. A separate optical output channel receives one of the output end fibers from each tapered fiber bundle.

Abstract: An optical device and methods of using an optical device are provided. The optical device includes a hollow-core fiber including a first portion and a second portion. The first portion includes a hollow core having a first diameter. The second portion includes a hollow core having a second diameter smaller than the first diameter. The difference between the first diameter and the second diameter is less than 10% of the first diameter.

Abstract: An Ortho Mode Transducer (OMT) comprising a main guide configured with a set of ports and at both ends for communicating a band of frequencies. The ports and are placed at a predetermined distance from each other to form a taper section. Branching waveguides are disposed around the main guide for extracting polarization signals from the main guide. Coupling apertures are disposed apart along the periphery of the main guide for coupling the branching waveguides to the main guide. The coupling apertures are aligned parallel to a longitudinal axis of the main guide and extended to the taper portion of the main guide, which enhances bandwidth performance without the need for additional extraneous impedance matching elements.

Abstract: A light coupler between an optical fiber (6) and a waveguide is made on a semiconductor-on-insulator substrate (1), this substrate (1) comprising a thin layer of semiconducting material in which the waveguide is made. The coupler comprises a light injector (5) and an adiabatic collector (4) made up with an inverted nanotip formed from the thin layer of semiconducting material. The injector (5) is formed on the insulator (3) and has a face (7) for receiving an end of the optical fiber (6). The adiabatic collector (4) has a cross-section which increases from a first end located on the side of said end of the optical fiber (6) right up to a second end which is connected to the waveguide, the injector (5) covering the adiabatic collector (4) and having a rib waveguide shape.

Abstract: An electric field sensor or a magnetic field sensor includes an optical fiber and an electro-optic layer or a magneto-optic layer. The electro-optic layer or a magneto-optic layer is provided on an end surface of an end portion of the optical fiber. The end surface of the optical fiber is a convex shape. The optical fiber may have the end portion with a shape of a substantial cone formed by extending the end portion, and the electro-optic layer or the magneto-optic layer may be formed on a side surface of a front end of the substantial cone. A dielectric layer may be further included between the optic layer and the end surface.

Abstract: There is described a double-clad fiber coupler (DCFC) composed of two double-clad fibers that have been fused together and tapered. The DCFC allows the propagation of light in the fundamental mode in its single-mode core with very little loss. Back reflected light may be collected two ways: by the core of the double-clad fiber and by the inner cladding of the double-clad fiber.

Abstract: Optical fiber lasers and components for optical fiber laser. An optical fiber laser can comprise a fiber laser cavity having a wavelength of operation at which the cavity provides output light, the cavity including optical fiber that guides light having the wavelength of operation, the fiber having first and second lengths, the first length having a core having a V-number at the wavelength of operation and a numerical aperture, the second length having a core that is multimode at the wavelength of operation and that has a V-number that is greater than the V-number of the core of the first length optical fiber at the wavelength of operation and a numerical aperture that is less than the numerical aperture of the core of the first length of optical fiber. At least one of the lengths comprises an active material that can provide light having the wavelength of operation via stimulated emission responsive to the optical fiber receiving pump light.

Abstract: A dental laser radiation chip includes an optical fiber including a fiber center section having a core and a clad and also including a jacket for covering the fiber center section. The dental laser radiation chip radiates a laser light having a wavelength of around 3 ?m. A tip section of the dental laser radiation chip has a shape of frustum tapering forward in an axial direction. The shape of frustum includes a tip face from which forward laser light is to be radiated forward in the axial direction and an inclining side face from which side laser light is to be radiated in a radial direction with respect to the axial direction. The tip face is mirror-surface-finished to have a surface roughness of 0.008 ?m. The inclining side face is rough-surface-finished to have a surface roughness of 0.4 ?m.

Abstract: An electronic-integration compatible photonic integrated circuit (EIC-PIC) for achieving high-performance computing and signal processing is provided. The electronic-integration compatible photonic integrated circuit comprises a plurality of electronic circuit structures and a plurality of photonic circuit structures. The electronic and photonic circuit structures are integrated by a process referred to as monolithic integration. An electronic circuit structure includes one or more electronic devices and a photonic circuit structure includes one or more photonic devices. The integration steps of electronic and photonic devices are further inserted into standard CMOS process. The photonic circuit structures and the electronic circuit structures are integrated to form the electronic-integration compatible photonic integrated circuit device.

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 coupler includes a first waveguide configured to supply a first optical signal having a wavelength and a second waveguide. The first optical signal having a first mode. The first waveguide has a tapered portion being spaced from the second waveguide by a distance sufficient to facilitate evanescent coupling of the first optical signal from the first waveguide to the second waveguide. A first effective refractive index of the first waveguide at a location in the tapered portion being equal to a second effective refractive index at a location in the second waveguide. The first effective refractive index being associated with the first mode and the second effective refractive index being associated with a second mode of a second optical signal having the wavelength. The second mode having a different order than the first mode, and the second waveguide being configured to supply the second optical signal.

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: Fiber amplifiers and oscillators include tapered waveguides such as optical fibers that permit multimode propagation but produce amplification and oscillation in a fundamental mode. The tapered waveguides generally are provided with an active dopant such as a rare earth element that is pumped with an optical pump source such as one or more semiconductor lasers. The active waveguide taper is selected to taper from a single or few mode section to a multimode section, and seed beam in a fundamental mode is provided to a section of the waveguide taper associated with a smaller optical mode, and an amplified beam exits the waveguide taper at a section associated with a larger optical mode.

Abstract: A method fabricates an optical switch comprising a microsphere coated with silicon nanocrystals. The method includes providing a silica optical fiber. The method further includes melting at least a portion of the fiber to form at least one silica microsphere. The method further includes coating the microsphere with a silica layer. The method further includes precipitating silicon nanocrystals within the silica layer by annealing the microsphere. The method further includes passivating the nanocrystals by annealing the microsphere in a hydrogen-containing atmosphere.

Abstract: An optical converter comprises: a first waveguide, a second waveguide, and a tapered waveguide arranged between both the waveguides, wherein heights of a core of the first waveguide and a core of the second waveguide are different; both ends in a direction of wave guiding of a core of the tapered waveguide are respectively connected to the core of the first waveguide and the core of the second waveguide; cross-sectional shapes and refractive indexes of cores of two waveguides that are connected change continuously or in a stepwise manner at each connection part; and a cross-sectional shape and refractive index of the core of the tapered waveguide change continuously or in a stepwise manner along a direction of wave guiding.

Abstract: Disclosed are systems and methods for improving the performance of systems for generating and detecting electromagnetic radiation at terahertz (THz) frequencies. Embodiments of the systems and methods include the fabrication and use of coupling tapers to provide efficient transfer of THz radiation between a photomixer and a waveguide that supports a propagating THz mode. A representative system comprises of a photomixer to convert high-frequency components of an optical pump signal into corresponding electrical THz frequencies, a waveguide that supports a propagating THz mode, and a matching taper that effectively converts the highly localized currents generated by the photomixer to the mode supported by the waveguide.

Abstract: A light guide of the tapered-waveguide type includes an input slab (30) for expanding a projected image between an input end and an output end, and an output slab (10) 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 (30) 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: A fiber loop formed by bending of a connection section between the first fiber and the second fiber includes a coupling region and an upper taper region as well as a down taper region arranged symmetrically on two sides of the coupling region. Then the fiber optic splitter with the fiber loop is assembled with a splitting ratio modulation mechanism. Thus the manufacturing of the fiber optic power splitter with variable splitting ratio is simplified and this favors production and applications of the device. Moreover, the splitting and modulation quality of the splitter are stable and are controlled precisely. Thus the economic benefits of the device in manufacturing, operation quality and product competitiveness are all improved.

Abstract: In an embodiment, a sensor element is provided. The sensor element may include a light input configured to receive input light, a sample chamber configured to accommodate a sample, and at least one polymer waveguide optically coupling the light input with the sample chamber, the at least one polymer waveguide including a first contact portion and a second contact portion, wherein at least a portion of the second contact portion may be arranged in the sample chamber. The second contact portion may include a different structure than the first contact portion so that a change of the light intensity of the input light passing through the second contact portion may be caused due to an interaction between the input light passing through the second contact portion and the sample, wherein the change of the light intensity of the input light passing through the second contact portion may be different from the change of the light intensity of the input light passing through the first contact portion.

Abstract: A main path in an optical waveguide with a light-emitting element has two sides faced to each other: one side has a plurality of branched points and the other side does not have any branched points. A width W of the main path becomes narrower as the main path moves away from a light-emitting element. An angle ? formed by the main path and a light guiding direction in each branched point of each branched path is 0.1° to 2.0°. An angle ? formed by the other side without branched points and the light guiding direction of the main path is 0.3° to 1.7°.

Abstract: A spot-size converter is equipped with a substrate, a clad that is formed on the substrate, a core that is embedded inside the clad, and an input/output end face. The core is tapered toward the input/output end face along a light propagation direction. In the clad, groove portions that expose a substrate face are formed extending as far as the input/output end face and on both sides of the core along the light propagation direction.

Abstract: A light emitting sign including a lightguide having a thickness not greater than 0.5 millimeters. The lightguide having an array of elongated legs extending therefrom, wherein each leg terminates in a bounding edge and is folded such that the bounding edges are stacked. At least one light source emits light into the stacked bounding edges. The light travels within the legs to the lightguide, with the light from each leg combining and totally internally reflecting within the lightguide. A plurality of light scattering features frustrate totally internally reflected light within the lightguide such that the light exits the sign in a light emitting area.

Abstract: Provided are an optical waveguide and a production method thereof which can constrict both the width and thickness of the SOI optical waveguide core layer in the same process and at the same time, simplify production process, and reduce optical losses. An optical waveguide includes a first clad layer formed on a semiconductor substrate; a first core layer formed on the upper side of the first clad layer with the use of a semiconductor material the refractive index of which is higher than that of the first clad layer; and a second clad layer formed on the upper side of the first core layer with the use of a material the refractive index of which is lower than that of the first core layer. The width of the first core layer is defined based on the width of an unoxidized semiconductor material sandwiched between oxide films the parts of which are thermally oxidized.

Abstract: The present invention includes a device and a method for fabricating a device that is an optical power mode transformer that accepts light in a mode transformation direction where the transformer is attached to or embedded in a semiconductor microchip and includes a first single or multimode optical input (SM) waveguide including a first core surrounded by a cladding, and, a second high contrast index grade (HC) waveguide including a second core having a tapered region and surrounded by said cladding, a portion of the tapered region of the core being embedded within the first optical input waveguide region with an embedded length sufficient for efficient light transfer from the first input waveguide to the said second waveguide wherein the embedded portion of the tapered region is fully surrounded by the first input waveguide along an axial and radial cross-section of the second waveguide in the mode transformation direction.

Abstract: A waveguide and resonator are formed on a lower cladding of a thermo optic device, each having a formation height that is substantially equal. Thereafter, the formation height of the waveguide is attenuated. In this manner, the aspect ratio as between the waveguide and resonator in an area where the waveguide and resonator front or face one another decreases (in comparison to the prior art) thereby restoring the synchronicity between the waveguide and the grating and allowing higher bandwidth configurations to be used. The waveguide attenuation is achieved by photomasking and etching the waveguide after the resonator and waveguide are formed. In one embodiment the photomasking and etching is performed after deposition of the upper cladding. In another, it is performed before the deposition. Thermo optic devices, thermo optic packages and fiber optic systems having these waveguides are also taught.

Abstract: An optical circuit comprises: a first waveguide; a second waveguide: and a third waveguide that converts mode field and direction of polarization of light of said first waveguide at the same time to perform wave guiding to said second waveguide: wherein large aspect ratio directions of corresponding ends of a core of said first waveguide and a core of said second waveguide differ from each other.

Abstract: A double clad fiber includes a core, a first cladding provided so as to cover the core, and a second cladding provided so as to cover the first cladding. The second cladding has a plurality of pores extending in a length direction and arranged so as to surround the first cladding. In at least one fiber end, the second cladding has been removed by mechanical processing so that the at least one fiber end is formed by the core and the first cladding.

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: An apparatus comprising an optical-mode-converter structure. The optical-mode-converter structure includes a tapered optical core on a planar substrate, an optical cladding layer covering the tapered optical core and a mode-expanding layer. The mode-expanding layer covers the tapered optical core and is located in-between the tapered optical core and the optical cladding layer. The mode-expanding layer has a refractive index that is in-between a refractive index of the tapered optical core and a refractive index of the optical cladding layer.

Abstract: An optical waveguide circuit includes: a lower cladding layer formed on a substrate; a first optical waveguide formed on the lower cladding layer so as to partition the lower cladding layer into a first portion and a second portion; a second optical waveguide formed on the first portion, the second optical waveguide including a tip end portion directed toward a side face of the first optical waveguide, the tip end portion being narrowed in a tapered manner; and a third optical waveguide formed on the second portion, the third optical waveguide including a tip end portion directed toward the tip end portion of the second optical waveguide, a tip end portion of the third optical waveguide being narrowed in a tapered manner.

Abstract: The present invention provides a light guide body that has a light incidence portion through which light enters the light guide body; a light reflecting portion positioned opposite a light emitting surface that extends from the light incidence portion in a longitudinal direction of the light guide body; and a tapered portion having an inner surface that gradually expands from the light incidence portion toward the light reflecting portion. The tapered portion has a light shielding portion to shield, from the light, a part of the light reflecting portion closest to the light incidence portion.

Abstract: An optical mode converter has a coupling waveguide and a receiving waveguide. The coupling waveguide has at an input end a first effective refractive index and includes a tapered core of a substantially constant refractive index with a substantially square cross section at the input end, which has a size that tapers down moving away from the input end. The coupling waveguide also has a cladding at least partially surrounding the tapered core. The receiving waveguide has a second effective refractive index at an output end and includes a core of a substantially constant refractive index greater than the refractive index of the tapered core of the coupling waveguide and a cladding at least partially surrounding the core. A side surface of the tapered core of the coupling waveguide is optically in contact, in a coupling portion, with the receiving waveguide so as to allow optical coupling between the coupling waveguide and the receiving waveguide.

Abstract: A system and method is provided for illuminating a subject using a light pipe that transmits light from a source, such as an LED ring illuminator to an outlet that directs the light appropriately as either bright field illumination, dark field illumination or both. The light pipe can include concentric cylinders, typically with a bright field illuminator nested within a dark field illuminator. The tip of the dark field illuminator may be angled so as to internally reflect light inwardly toward the central optical axis of a camera at a low angle. The tip can be located near the focal plane of the camera for the desired field of view. The field of view of the camera sensor can be modified to reject data outside of a illumination field of a particular shape. This illumination field can be created by shaping the light pipe in a predetermined form that projects the modified illumination field.

Abstract: An apparatus for optically coupling light between optical transmission components is provided. The apparatus includes first and second optical transmission components wherein the first optical transmission component includes a planar optical waveguide, a grating coupler, and a transparent substrate and the second optical transmission component includes an optical fiber. Preferably, the planar optical waveguide includes silicon and the transparent substrate includes glass. Methods for coupling light between optical transmission components are also provided.

Abstract: Devices and techniques are described for connecting each of plurality of terminals to respective individual cores of a multicore fiber. Each of the plurality of terminals is provided with a respective length of a single-core fiber. The single-core fibers are configured to maintain modal properties that arc substantially the same, within a tolerance range, at the front and rear ends, as the single-core fiber is tapered. The single-core fibers are assembled together. The front end of the assembly is tapered to form a front cross-section in which the single-core fiber cores are arranged in a configuration matching that of the cores of the multicore fiber.

Abstract: A process for forming a mode size converter with an out-of-plane taper formed during deposition with a shadow mask is disclosed. Mode-size converters according to the present invention can have any number of configurations. Measured coupling efficiencies for waveguides with mode size converters according to the present invention show marked improvement.

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: A transition part (1) between two optical waveguides (2,3) with different index contrast is characterised in that the transition part (1) includes a non-adiabatically up-tapered longitudinal section (8), and in that the transition (7) between the two waveguides (2,3) is arranged after the up-tapered longitudinal section (8) as seen along the main direction (L) of propagation of the light. A method of manufacturing the transition part is also described.

Abstract: An optical waveguide for a touch panel in which the intensity of light beams emitted from light-emitting portions of a plurality of light-emitting cores in the form of branches is substantially uniform independently of the branch position of the light-emitting cores, and a touch panel using the same. An optical waveguide for a touch panel is provided in which a plurality of light-emitting cores 33 are formed by dividing a tip portion of a single original core into branches. A portion extending from a basal portion 32b of the original core to a branch point 32c at which the division into the branches serving as the light-emitting cores 33 starts is an isosceles triangular portion 32 gradually widened from the basal portion 32b into the shape of an isosceles triangle. The isosceles triangle has a taper angle ? in the range greater than 0 degrees and less than 15 degrees.

Abstract: An optical coupler is formed of a low index material and exhibits a mode field diameter suitable to provide efficient coupling between a free space optical signal (of large mode field diameter) and a single mode high index waveguide formed on an optical substrate. One embodiment comprises an antiresonant reflecting optical waveguide (ARROW) structure in conjunction with an embedded (high index) nanotaper coupling waveguide. Another embodiment utilizes a low index waveguide structure disposed in an overlapped arrangement with a high index nanotaper coupling waveguide. The low index waveguide itself includes a tapered region that overlies the nanotaper coupling waveguide to facilitate the transfer of the optical energy from the low index waveguide into an associated single mode high index waveguide. Methods of forming these devices using CMOS processes are also disclosed.

Abstract: A fiber optic interconnect device includes a silicon substrate having at least one groove formed therein. The groove includes a pair of sidewalls and a first end disposed at an end of the pair of sidewalls. The device also includes an optical fiber disposed in the groove, the optical fiber having a cylindrical body, an endface formed on an end of the cylindrical body, and a multi-faceted mirror formed on the endface, and a light source adapted to transmit light to the multifaceted mirror to launch light through the optical fiber to a detector.

Abstract: At least two single-mode optical fibers are fused together such that their cores are separated by only a few microns to serve as a capture element of an incoming beam of light in an optical terminal.

Abstract: An optical waveguide, on account of its ability to apply phase resonance of a wavelength and of a first and second triangular plate-like spot size converter members formed of the same material as a core material and being arranged and formed in a substantially symmetrical structure, can promote shortening of the waveguide length and contrive to reduce the size of the optical waveguide itself. Further, an optical waveguide having excellent spot size conversion efficiency can be obtained even in a reduced size.

Abstract: A method of forming an optical fibre tip, the method including, roughening at least part of an end portion of the optical fibre; and, etching the roughed end portion to thereby form an optical fibre tip.