Abstract: The invention provides a planar optical waveguide circuit capable of preventing part of the input signal light that has not been combined in the waveguide and propagates as leaked light from interfering with the output signal. A planar optical waveguide circuit having an optical waveguide embedded in a cladding layer includes: a plurality of parallel output optical waveguides configured to emit light from a same end face; a groove having a reflective interface formed at an angle of +45 degrees relative to the output optical waveguides and configured to reflect leaked light propagating in the cladding layer; and a groove having a reflective interface formed at an angle of ?45 degrees, the reflective interface formed at an angle of +45 degrees, the output optical waveguide, and the reflective interface formed at ?45 degrees being arranged repeatedly in that order.

Abstract: An optical fiber combiner comprises a double-clad fiber (DCF) and one or more multimode fibers (MMFs). DCF comprises a transition portion, a DCF taper portion, and an output section coupling to the DCF taper portion, whereas each of MMFs comprises an MMF taper configured to be fused around DCF in the transition portion. MMFs are configured to carry a combined optical energy (COE) and to couple to DCF. COE passes through the MMF taper with larger divergence of higher-order modes generated and coupled into DCF, whereas the DCF taper portion can partially offset the larger divergence. COE coupled, when traced through the output section, emerges in the air with a smaller output beam divergence of the higher-order modes, thereby preserving some of the higher-order modes in the output section and increasing a coupling efficiency of COE coupled from MMFs to DCF with improved thermal performance.

Abstract: A super-resolution optical imaging method and system, including: providing a periodic monolayer array of dielectric spheres or cylinders with a sufficiently small period such that the fields-of-view produced by the spheres or cylinders overlap providing an enlarged field-of-view; wherein the dielectric spheres or cylinders are fixed in their positions such that the array is adapted to be brought adjacent to a sample to be optically imaged as a whole; and applying pressure to the array to reduce a gap separating the dielectric spheres or cylinders from the sample to achieve super-resolution imaging with the enlarged field-of-view. The super-resolution optical imaging method and system further comprising positioning the dielectric spheres or cylinders adjacent to one another in the array by air suction through a periodic micro-hole array providing a monolayer arrangement with a negligible defect rate.

Abstract: A system and method for optimizing optical communication for autonomous vehicles, including: determining a predetermined route of a vehicle equipped with an optical communication device (OCD) including an array of micromirrors; determining a location of at least one infrastructure unit along the predetermined route; determining optimal angles for the array of micromirrors based on the predetermined route and the determined location of the at least one infrastructure unit to optimize optical communication between the OCD and the at least one infrastructure unit; and adjusting the array of micromirrors based on the determined optimal angles.

Abstract: An optical fiber combiner comprises a double-clad fiber (DCF) and one or more multimode fibers (MMFs). DCF comprises a transition portion, a first taper portion, and an output section coupling to the first taper portion, whereas each of MMFs comprises a second taper configured to be fused around DCF in the transition portion. MMFs are configured to carry a combined optical energy (COE) and to couple to DCF. COE passes through the second taper with larger divergence of higher-order modes generated and coupled into DCF, whereas the first taper portion can partially offset the larger divergence. COE coupled, when traced through the output section, emerges in air with a smaller output beam divergence of the higher-order modes, thereby preserving some of the higher-order modes in the output section and increasing a coupling efficiency of COE coupled from MMFs to DCF with improved thermal performance.

Abstract: A waveguide illuminator includes an input waveguide, a waveguide splitter coupled to the input waveguide, and a waveguide array coupled to the waveguide splitter. The waveguide array includes an array of out-couplers out-coupling portions of the split light beam to form an array of out-coupled beam portions for illuminating a display panel. To reduce optical interference, the waveguide illuminator may have two interlaced waveguide arrays energized by two different light sources. Output polarizations of neighboring light pixels of a display illuminated with such waveguide illuminator may be orthogonal to each other. The frames to be displayed may be broken down into sequentially displayed sub-frames with interleaved pixels.

Abstract: A continuous optical beat laser element for generating terahertz (THz) waves and a laser source using same includes periodically poled lithium niobate (ppLN) crystals arranged along a predetermined direction forming a surface generally parallel to the predetermined direction. A Ti diffused region is applied on the surface and an array of gold nanowires are applied on the Ti diffused region to form a gold metal-insulator-metal (MIM) element that optimizes coupling and channeling of THz radiation from the crystals into the gold nanowires. The system provides a simple, stable, compact and cost-effective THz source using a widely tunable C-band SOA-based laser to excite a non-linear photo-mixer to produce terahertz radiation that ranges from 0.8 to 2.51 THz at room temperature. This laser source can be modified into an all fiber-based THz generator by embedding ppLN crystals in a fiber filament configuration resulting in less absorption and producing high output power.

Abstract: A photonic device for splitting optical beams includes an input port configured to receive an input beam having an input power, a power splitter including perturbation segments arranged in a first region and a second region of a guide material having a first refractive index, each segment having a second refractive index, wherein the first region is configured to split the input beam into a first beam and a second beam, wherein and the second region is configured to separately guide the first and second beams, wherein the first refractive index is greater than the second refractive index, and output ports including first and second output ports connected the power splitter to respectively receive and transmit the first and second beams.

Abstract: An optical semiconductor device comprises a semiconductor substrate, an optical 90-degree hybrid circuit provided on the substrate, a plurality of input optical waveguides provided on the substrate, and a plurality of output optical waveguides provided on the substrate. The plurality of input optical waveguides is optically coupled to input ends of the optical 90-degree hybrid circuit. The plurality of output optical waveguides is optically coupled to output ends of the optical 90-degree hybrid circuit. Each of the plurality of input optical waveguides includes a first curving portion and a first straight portion adjacent to the first curving portion, and each of the plurality of output optical waveguides includes a second curving portion. A central axis of the first curving portion is inwardly offset with respect to a central axis of the first straight portion, and a central axis of the second curving portion follows a raised sine curve.

Abstract: Aspects of the present disclosure are directed toward designs and methods improving optical sensing, wavelength division multiplexed (WDM) telecommunication transceivers, WDM add/drops, and spectrometer techniques that may benefit from a stable wavelength reference. The disclosed designs and methods are useful in the manufacture of a stable wavelength reference that may compensate for temperature variations.

Abstract: A system includes an optical fiber situated to propagate a laser beam received from a laser source to an output of the optical fiber, a first cladding light stripper optically coupled to the optical fiber and situated to extract at least a portion of forward-propagating cladding light in the optical fiber, and a second cladding light stripper optically coupled to the optical fiber between the first cladding light stripper and the optical fiber output and situated to extract at least a portion of backward-propagating cladding light in the optical fiber.

Abstract: An optical fiber monitoring system monitors an inter-building optical fiber connecting a first building and a second building. The optical fiber monitoring system includes a first visualization panel provided in the first building and optically connected to an one end of the inter-building optical fiber, a second visualization panel provided in the second building and optically connected to an other end of the inter-building optical fiber, and a monitoring light source provided in the first building to input a monitoring light into the inter-building optical fiber. The first visualization panel includes a first photosensor that partially leaks the monitoring light inputted into the inter-building optical fiber from the monitoring light source and detects an amount of a leaked light. The second visualization panel includes a second photosensor that partially leaks a light from the inter-building optical fiber and detects amount of a leaked light.

Abstract: An optical switch and a wavelength division multiplexing optical system are disclosed. In an embodiment an optical switch includes an input port array, an input collimator array, an input micromirror array, an output micromirror array, an output collimator array, and an output port array. All input micromirrors included in the input micromirror array can be deflected in two mutually perpendicular directions. The maximum movable ranges of reflected light that is output after all the input micromirrors reflect incident light with the same incident angle have no common intersection on a plane on which the output micromirror array is located or have a common intersection, and an area of the intersection is less than an area of a reflection region of the output micromirror array.

Abstract: An optical tap includes a support with a first port facing a first ferrule supporting a first fiber along a first axis. A beamsplitter is connected to the support and intersected by the first axis. A second port is fastened to the support and facing a second ferrule supporting a second fiber along a second axis that intersects the beamsplitter. A third port is fastened to the support and facing a third ferrule supporting a third fiber along a third axis that intersects the beamsplitter, wherein the beamsplitter splits a first light signal from the first port to sends first and second portions of the first signal to the second and third ports, respectively. When the beamsplitter may optionally be configured as a polarizing element and include elements configured to rotate relative to each other to change a ratio of the first and second portions.

Abstract: In an optical modulator directional measurement system embodiment, one or more modulation waves may be measured and directionally discriminated by measuring the modulations of one or more lightwaves. The optical modulator transmission function magnitude for a most phase-matched modulation may be substantially greater than that for other modulations. At sufficiently high modulation frequency, the most phase-matched modulation magnitude may be substantially greater than the other modulation magnitudes. Accordingly, a modulation wave may be distinctly measured by measuring the modulation of the most phase-matched lightwave.

Abstract: A method is disclosed to provide improved fiber inline optical power monitoring that eliminates the need for micro-bending the fiber or for fabricating micro-reflector on the fiber. A subset of light is tapped through an offset at a fusion-spliced upstream and downstream optic fiber, and is guided out of the downstream fiber by a light guide to a reflector and photo-sensing measurement. The disclosed inline fiber monitoring is thus cost effective, wavelength independence, reliable, stable, and also causes less light transmission loss.

Abstract: A position-measuring device for detecting the position of two objects movable relative to each other, includes a measuring standard that is joined to one of the two objects, as well as a scanning system for scanning the measuring standard, the scanning system being joined to the other of the two objects. The scanning system permits a simultaneous determination of position along a first lateral shift direction and along a vertical shift direction of the objects. To that end, on the part of the scanning system, two scanning beam paths are formed, in which a group of phase-shifted signals is able to be generated in each case at the output end from interfering partial beams of rays. In addition, via the scanning system, at least a third scanning beam path is formed, by which it is possible to determine position along a second lateral shift direction of the objects.

Abstract: A device includes integrated circuit chips mounted on one another. At least one component for protecting elements of a second chip is formed in a first chip. The chips may be of the SOI type, with the first chip including a first SOI layer having a first thickness and the second chip including a second SOI layer having a second thickness smaller than the first thickness. The first chip including the component for protecting may include an optical waveguide with the component for protecting formed adjacent the optical waveguide.

Abstract: A compact, low-loss and wavelength insensitive Y-junction for submicron silicon waveguides. The design was performed using FDTD and particle swarm optimization (PSO). The device was fabricated in a 248 nm CMOS line. Measured average insertion loss is 0.28±0.02 dB across an 8-inch wafer. The device footprint is less than 1.2 ?m×2 ?m, orders of magnitude smaller than MMI and directional couplers.

Abstract: Methods and apparatuses are provided to digitize an analog multi-channel RF narrowcast signal in an overlay system by dividing the signal into a plurality of subband signals and digitizing each subband signal using practical A/D converters.

Abstract: A switch is inserted and connected between a first portion and a second portion of an HPD line. The switch connects the first portion to the second portion when an HPD signal is outputted to the second portion. The switch cuts off the connection between the first portion and the second portion when the HPD signal is not outputted to the second portion. An AND gate generates a connection state detection signal that represents the connection state of an HDMI optical active cable, and outputs the connection state detection signal to a switch.

Abstract: An optical fiber combiner 1 has: a plurality of input optical fibers 20; a plurality of divergence angle reducing members 50 which lights emitted from the respective input optical fibers 20 enter and which emits the lights from the input optical fibers 20 at divergence angles made lower than divergence angles upon entrance; a bridge fiber 30 which the lights emitted from the respective divergence angle reducing members 50 enter and which has a tapered portion 34 which has a portion in which the lights propagate and a diameter of which is gradually reduced apart from a divergence angle reducing member 50 side; and an output optical fiber 40 which a light emitted from a side of the bridge fiber 30 opposite to the divergence angle reducing member 50 side enters.

Abstract: A light intensity subtractor according to one aspect of the present invention includes a light subtraction unit, a feedback circuit, a light input port, a first light output port, and a second light output port. The light subtraction unit receives input light through the light input port, outputs first output light to the first light output port, and outputs second output light to the second light output port. The light subtraction unit generates the first output light by reducing the light intensity of the second output light from the light intensity of the input light in accordance with a control voltage. The feedback circuit is connected to the light subtraction unit through the second light output port, and outputs the control voltage in accordance with the light intensity of the received second output light.

Abstract: A surface-plasmon-polaritons (SPPs) tunable optical resonant ring filter that includes an SPPs waveguide, an SPPs tunable directional coupler, and an SPPs tunable resonant ring. The tunabilities of the resonant frequency, the resonant depth, and the filtering bandwidth are achieved by tuning the loss and transmission phase of the resonant ring and the coupling ratio of the directional coupler. Since the metal core layer of the SPPs waveguide is capable of multiplexing electro-optical signals, the SPPs tunable optical resonant ring filter can be used not only in an integrated optics system, but also in an integrated electro-optics hybrid system.

Abstract: At the time of assembly of an optical transmission/reception module, a test variable wavelength light source 22 for outputting a test light signal is connected to a connector 8 of an optical fiber 7, and a large-diameter PD 23 measures a transmission loss in a light wavelength band limiting filter 12 while a rotational position determining unit 24 rotates a fiber ferrule 5, so that the rotational position determining unit 24 determines the rotational position ?loss-min of the fiber ferrule 5 which minimizes the transmission loss in the light wavelength band limiting filter 12, and aligns the fiber ferrule 5 at the rotational position ?loss-min.

Abstract: Method for modifying the splitting or combining ratio of a first multimode interference (MMI) coupler (100), which first coupler is arranged to convey light from one or several input waveguides to one or several output waveguides, wherein a film (103a) of a material is arranged over the first coupler, wherein the film is strained so that a force is applied by the film to the surface of the first coupler, and so that the refractive index profile in the material of the first coupler changes as a consequence of the force, and wherein the splitting or combining ratio is modified as a consequence of the changed refractive index profile.

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 disclosure relates to an optical device that includes an optical splitting component that optically couples an optical input fiber to a plurality of optical output fibers. The optical output fibers have non-connectorized free ends that have been processed to reduce the ability of the non-connectorized free ends to reflect light back towards the optical splitting component.

Abstract: An optical power splitter includes a zig-zag and a reflector element associated with the zig-zag. The zig-zag is to split an input signal based on the reflector element, and output a plurality of split signals.

Abstract: An optical device includes at least one optical waveguide including a plurality of elongate portions. Light propagates sequentially and generally along the elongate portions. At least two elongate portions of the plurality of elongate portions are generally planar with one another and are adjacent and generally parallel to one another. The at least two elongate portions are optically coupled to one another such that the light is coupled between the at least two elongate portions in a direction generally perpendicular to the at least two elongate portions as the light propagates generally along the at least two elongate portions.

Abstract: Waveguide array optical power splitters that provide compact, low-cost implementation of optical power splitting for one and two dimensional optical waveguide arrays are disclosed. The optical power splitters do not introduce mode dependent loss and preserve polarization, enabling the optical power splitters to be used with multimode and single mode light sources. In one aspect, an optical power splitter includes a beamsplitter to receive a plurality of incident beams of light. The beamsplitter splits each incident beam of light into a plurality of output beams of light with each output beam output in a different direction from the beamsplitter. The optical power splitter includes a first set of lenses with each lens to approximately collimate one of the incident beams of light, and includes a second set of lenses with each lens to focus the output beams of light.

Abstract: There is provided a waveguide combiner/splitter comprising an input waveguide, a first and a second waveguide matching section, and at least a first and a second output waveguide. The lengths and the widths of the matching sections may be adjusted for tuning to frequency bands of interest. The combiner/splitter may be incorporated into a corporate feed structure for use in an antenna system.

Abstract: An antiviral optical tap system for a fiber optic circuit that uses an Optical Circulator or an Isolator or any other unidirectional optical device that is connected to the secondary optical tap output of an optical tap that prevents unwanted optical signals or optical noise from entering a fiber optic circuit through the secondary optical tap output and allows optical signals to pass to an external device through the Optical Circulator or Isolator or any other unidirectional device.

Abstract: Apparatus and method for in-line cladding-light dissipation including forming a light-scattering surface on the optical fiber such that the light-scattering surface scatters cladding light away from the optical fiber. In some embodiments, the apparatus includes an optical fiber having a core and a first cladding layer that surrounds the core, wherein a first portion of the optical fiber has a light-scattering exterior surface. Some embodiments further include a transparent enclosure, wherein the transparent enclosure includes an opening that extends from a first end of the transparent enclosure to a second end of the transparent enclosure, and wherein at least the first portion of the optical fiber is located within the opening of the transparent enclosure. Some embodiments include a light-absorbing housing that surrounds the optical fiber and the transparent enclosure and is configured to absorb the light scattered away from the optical fiber by the light-scattering exterior surface.

Abstract: An optical device includes a waveguide slab, first and second input port couplers, and first and second output port couplers located over a planar optical substrate. The waveguide slab has a plane of symmetry. The first and second input port couplers extend from the waveguide slab and have an input coupler pair axis located about midway between the first and second input port couplers. The input coupler pair axis is offset at a nonzero first distance from the plane of symmetry. The first and second output port couplers extend from the waveguide slab and have an output coupler pair axis located about midway between the first and second output port couplers. The output coupler pair axis is offset at a different nonzero second distance from the plane of symmetry.

Abstract: In order to provide a method of manufacturing an optical waveguide, which enables the formation of a smooth mirror face, the following method of manufacturing an optical waveguide having a mirror face is used. The method includes: a photocurable resin sheet laminating step of laminating an uncured photocurable resin sheet for forming a core on a surface of a first cladding layer that has been formed on a substrate; a mirror face forming step of forming a mirror face for guiding light to the core by pressing a die provided with a blade having, in a cross-section, a 45° inclined plane into the photocurable resin sheet; a core forming step of forming a core having the mirror face positioned at an end thereof by selectively exposing to light, and developing, the photocurable resin sheet; and a cladding layer forming step of forming a second cladding layer so as to bury the core.

Abstract: An optical light splitter includes or is connected to at least two input waveguides (4; 6, 7; 18, 19; 32,33) for light. The light splitter (1, 2, 30, 40), on the side opposite to the input waveguide or input waveguides (4; 6, 7; 18, 19; 32, 33; 41, 42) transitions into at most one output waveguide (8, 10, 20, 34) in the direction of propagation of the incoming light. A surface (14, 25, 31, 45) is present set at an angle to the direction of propagation of the light in that part of the light splitter that is opposite to the input waveguide or input waveguides, the surface is present where the light splitter has an image from incoming light, and internal corners are not present in the part.

Abstract: The optical coupler module for converting and transmitting electrical/optical signals includes a semiconductor substrate, a first film, a second film, an electrical transmission unit, at least one signal conversion unit and an optical waveguide structure. The first film and the second film are formed on opposite surfaces of the semiconductor substrate. The signal conversion unit and the optical waveguide structure are disposed on opposite sides of the semiconductor substrate. The optical waveguide structure has a reflector and a waveguide body. The optical signal generated from the signal conversion unit sequentially passes the first film, the semiconductor substrate and the second film and enters the optical waveguide structure. Then, the optical signal is reflected by the reflector and transmitted in the waveguide body to be outputted. Alternatively, the optical signal is transmitted in a reverse direction from the optical waveguide structure to the signal conversion unit.

Abstract: A coherent optical detector having a waveguide circuit, in which a plurality of waveguides are connected to a waveguide grating. In a representative embodiment, the waveguide grating serves at least three different functions, e.g., those of a fiber-optic coupler, a polarization splitter, and two power splitters, one for each of two orthogonal polarizations. Various embodiments of the coherent optical detector can be used to demodulate various forms of polarization-division-multiplexed (PDM) QAM- and/or PSK-modulated optical communication signals.

Abstract: New designs of optical devices, particularly for dropping a selected wavelength or a group of wavelengths as well as demultiplexing a multiplexed signal into several signals, are disclosed. An optical device employs thin film filters with reflectors to reassemble as a fiber Bragg grating. Depending on implementation, a reflector may be a mirror or a coated substrate disposed in a unique way to reflect a light beam from a filter back to a common port of a device. The reflector may also be coated accordingly to bypass a certain portion of the light beam for other purposes. As a result, the optical devices so designed in accordance with the present invention are amenable to small footprint, enhanced impact performance, lower cost, and easier manufacturing process.

Abstract: The present invention provides improved collimating lens assemblies (32) which include: a singlemode fiber (38) terminating in a distal end; a step-index multimode fiber (44) having a proximal end abutting to the singlemode fiber distal end, and having a distal end; a graded-index multimode fiber (45) having a proximal end abutting the step-index multimode fiber distal end, and having a distal end; and a collimating lens (34) longitudinally spaced from the graded-index multimode fiber distal end by an intermediate air gap (43), and operatively arranged to collimate light rays emanating from the graded-index multimode fiber distal end. The improved collimating lens assembly is characterized by the fact that there is no epoxy, silicone gel or index-matching material between the graded-index multimode fiber distal end and the collimating lens.

Abstract: The optical coupler module for converting and transmitting electrical/optical signals includes a semiconductor substrate, a first film, a second film, an electrical transmission unit, at least one signal conversion unit and an optical waveguide structure. The first film and the second film are formed on opposite surfaces of the semiconductor substrate. The signal conversion unit and the optical waveguide structure are disposed on opposite sides of the semiconductor substrate. The optical waveguide structure has a reflector and a waveguide body. The optical signal generated from the signal conversion unit sequentially passes the first film, the semiconductor substrate and the second film and enters the optical waveguide structure. Then, the optical signal is reflected by the reflector and transmitted in the waveguide body to be outputted. Alternatively, the optical signal is transmitted in a reverse direction from the optical waveguide structure to the signal conversion unit.

Abstract: An integrated optical coupler including in the medium separating a first integrated waveguide from a second substantially parallel integrated waveguide, a succession of strips parallel to one another and orthogonal to the general direction of the waveguides, said strips being made of a material having an absorption preventing the propagation of an electromagnetic wave across its volume, and having: a length H equal to k?/2nmedium, where k is an integer, ? is the central wavelength used, and nmedium is the optical index of the medium between the waveguides; a period P smaller than ?/2nmedium; and ends at a distance shorter than ?/10 from the waveguides.

Abstract: A single-stage 1×5 grating-assisted wavelength division multiplexer is provided. A grating-assisted asymmetric Mach-Zehnder interferometer, a plurality of grating-assisted cross-state directional couplers and a plurality of novel side-band eliminators are combined to form the multiplexer. Only general gratings are required, not Bragg grating, for 5-channel wavelength division multiplexing in a single stage. A nearly ideal square-like band-pass filtering passband is obtained. The present disclosure can be used as a core device in IC-to-IC optical interconnects for multiplexing and demultiplexing of an optical transceiver. The present disclosure has a small size and good performance.

Abstract: The multi-channel optical device includes multiple laser cavities that each reflects a different light channel back and forth between reflective components. One of the reflective components is common to all of the laser cavities in that the common reflective component receives the channels from each of the laser cavities and reflects the received channels. The laser cavities also share a multiplexer that receives the channels reflected by the common reflective device and demultiplexes the channels into demultiplexed channels. A portion of the reflective components are partial return devices that each receives one of the demultiplexed channels. Each of the partial return devices transmits a portion of the demultiplexed channel received by that partial return device. The transmitted portion of the demultiplexed channel exits the laser cavity. Additionally, each of the partial return devices reflects a portion of the demultiplexed channel receive by that partial return device.

Abstract: Methods of using an optical device capable of distributing the optical power presented at an input to specified ratios in two output ports. The devices and methods described herein have the ability to broaden the range of wavelengths over which the splitting ratio is even, or substantially even. Methods involve achieving a desired splitting ratio over a broad or ultra-broad wavelength range.

Abstract: An optical channel tap assembly comprises a first N by M waveguide array including a first set of optical channels to convey optical signals along a first set of conveyance paths. The optical channel tap assembly also comprises a second N by M waveguide array including a second set of optical channels to convey the optical signals along a second set of conveyance paths, the optical signals received from the first set of conveyance paths. Additionally, the optical channel tap assembly comprises a beam splitter, disposed between the first N by M waveguide array and the second N by M waveguide array, to divert a first portion of power from the optical signals away from the second N by M waveguide array while allowing a second portion of power from the optical signals to propagate into the second N by M waveguide array.

Abstract: A device for amplifying optical signals propagating in optical fibers comprising a double cladding fiber amplifier having multiple gain stages, a port for coupling pump light into the double cladding fiber amplifier, and a double cladding fiber coupler for splitting the coupled pump light between the gain stages of the double cladding fiber amplifier. Also, a method for amplifying optical signals propagating in optical fibers comprising the steps of providing a double cladding fiber amplifier having multiple gain stages, coupling pump light into the double cladding fiber amplifier, and splitting the coupled pump light between the gain stages of the double cladding fiber amplifier.

Abstract: Apparatus and method for in-line cladding-light dissipation including forming a light-scattering surface on the optical fiber such that the light-scattering surface scatters cladding light away from the optical fiber. In some embodiments, the apparatus includes an optical fiber having a core and a first cladding layer that surrounds the core, wherein a first portion of the optical fiber has a light-scattering exterior surface. Some embodiments further include a transparent enclosure, wherein the transparent enclosure includes an opening that extends from a first end of the transparent enclosure to a second end of the transparent enclosure, and wherein at least the first portion of the optical fiber is located within the opening of the transparent enclosure. Some embodiments include a light-absorbing housing that surrounds the optical fiber and the transparent enclosure and is configured to absorb the light scattered away from the optical fiber by the light-scattering exterior surface.

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.