327results about "Microstructured optical fibre" patented technology

A method for preparing electro-optical polymer-liquid crystal photonic crystals, comprising: disposing between at least two optically transparent electrode plates, a polymer-dispersed liquid crystal material that comprises, before exposure:(a) a polymerizable monomer comprising at least one acrylate;(b) a liquid crystal;(c) a chain-extending monomer;(d) a coinitiator;(e) a photoinitiator; and(f) a long chain aliphatic acid;and exposing this polymer-dispersed liquid crystal material to light in an interference pattern.

Light diffusing optical fibers and methods for producing light diffusing optical fibers are disclosed. In one embodiment, a light diffusing optical fiber includes a core portion formed from silica glass and comprising a plurality of helical void randomly distributed in the core portion of the optical fiber and wrapped around the long axis of the optical fiber. A pitch of the helical voids may vary along the axial length of the light diffusing optical fiber in order to achieve the desired illumination along the length of the optical fiber. A cladding may surround the core portion. Light guided by the core portion is scattered by the helical voids radially outward, through the cladding, such that the light diffusing optical fiber emits light with a predetermined intensity over an axial length of the light diffusing optical fiber, the light diffusing optical fiber having a scattering induced attenuation loss greater than about 0.2 dB / m at a wavelength of 550 nm.

A non-imaging optical collecting and concentrating apparatus for use in i.e., optical communications, passive lighting, and solar power applications that is relatively immune from optical incidence angle(s) and therefore does not need to track the movement of the sun to efficiently collect and concentrate optical energy. The apparatus includes a non-planar support structure having a source-facing entrance and an energy-outputting exit. An interior surface of the structure includes a scattering, reflecting and / or diffractive medium such as a photonic bandgap structure to enhance the collection and concentration efficiency.

A random array of holes is created in an optical fiber by gas generated during fiber drawing. The gas forms bubbles which are drawn into long, microscopic holes. The gas is created by a gas generating material such as silicon nitride. Silicon nitride oxidizes to produce nitrogen oxides when heated. The gas generating material can alternatively be silicon carbide or other nitrides or carbides. The random holes can provide cladding for optical confinement when located around a fiber core. The random holes can also be present in the fiber core. The fibers can be made of silica. The present random hole fibers are particularly useful as pressure sensors since they experience a large wavelength dependant increase in optical loss when pressure or force is applied.

An apparatus and method for compensating for mode-profile distortions caused by bending optical fibers having large mode areas. In various embodiments, the invention micro-structures the index of refraction in the core and surrounding areas of the inner cladding from the inner bend radius to the outer bend radius in a manner that compensates for the index changes that are otherwise induced in the index profile by the geometry and / or stresses to the fiber caused by the bending.

Included among the many structures described herein are photonic bandgap fibers designed to provide a desired dispersion spectrum. Additionally, designs for achieving wide transmission bands and lower transmission loss are also discussed. For example, in some fiber designs, smaller dimensions of high index material in the cladding and large core size provide small flat dispersion over a wide spectral range. In other examples, the thickness of the high index ring-shaped region closest to the core has sufficiently large dimensions to provide negative dispersion or zero dispersion at a desired wavelength. Additionally, low index cladding features distributed along concentric rings or circles may be used for achieving wide bandgaps.

An apparatus and method for compensating for mode-profile distortions caused by bending optical fibers having large mode areas. In various embodiments, the invention micro-structures the index of refraction in the core and surrounding areas of the inner cladding from the inner bend radius to the outer bend radius in a manner that compensates for the index changes that are otherwise induced in the index profile by the geometry and / or stresses to the fiber caused by the bending. Some embodiments of an apparatus and method include a fiber having a plurality of substantially parallel cores, the fiber including a straight section and a curved section; guiding signal light primarily in a second core in the straight section; guiding the signal light from the second core into a first core between the straight section and the curved section; and guiding the signal light primarily in the first core in the curved section.

An optical fiber, comprising: (i) a rare earth doped silica based elongated core with a first refractive index (n1) with an aspect ratio of 1:5 to 1; (ii) a silica based moat abutting and at least substantially surrounding the core, the moat having a refractive index n2, wherein n2<n1; (iii) a silica based inner cladding surrounding the moat, the inner cladding having a third refractive index (n3), wherein n1>n3; and n3>n2; (iv) a silica based outer cladding surrounding said inner cladding, the outer cladding having a fourth refractive index (n4), such that n4<n3; the optical fiber exhibits single polarization at the operating wavelength band.

A microstructured fiber having a cladding comprising a number of elongated features that are arranged to provide concentric circular or polygonial regions surrounding the fiber core. The cladding comprises a plurality of concentric cladding regions, at least some of which comprising cladding features. Cladding regions comprising cladding features of a relatively low index type are arranged alternatingly with cladding regions of a relatively high index type. The cladding features are arranged in a non-periodic manner when viewed in a cross section of the fiber. The cladding enables waveguidance by photonic bandgap effects in the fiber core. An optical fiber of this type may be used for light guidance in hollow core fibers for high power transmission. The special cladding structure may also provide strong positive or negative dispersion of light guided through the fiber-making the fiber useful for telecommunication applications.

A method including the steps of providing a light-diffusing optical fiber (12a) having a glass core (20), a cladding (40) surrounding the core (20), and a plurality of nano-sized structures in the form of voids (32) situated within said core (20) or at a core-cladding boundary; cleaving the light-diffusing fiber (12a), thereby forming a cleaved end face (66); and applying energy to one or more of 1) the cleaved end face (66) and 2) the light-diffusing fiber (12b) along a portion of the length thereof adjacent the cleaved end face (66), the amount of energy being sufficient to collapse and seal the voids (32) exposed at the cleaved end face (66), leaving a sealed cleaved end face (68). A lens may then be attached to the sealed cleaved end face (68), or the sealed cleaved end face (68) may be softened sufficiently to induce formation of a lensing surface such as a convex lensing surface (60) on the sealed end face (68).

A wearable device assembly includes a device module having a component housing with a display configured to present information to the user, an auxiliary housing unit remote from the component housing, and a connecting member extending between the housing unit and the auxiliary housing unit. The device also includes a head retention structure having a center support with a nosepiece extending therefrom, a first side arm extending from the center frame support on a first side thereof, and an attachment arm extending from the center support on a second side thereof. The device module and the head retention structure are configured for releasable assembly together by removably attaching a first attachment feature on the connecting arm with the second attachment feature on the retention member. When assembled together, the device assembly is wearable on the head of the user.

Methods of preparing porous optical materials are provided. These methods allow for the selection of the desired pore size and level of porosity in the porous optical material. Such methods utilize a preformed polymeric porogen.

A laser device comprising a pump source (10) operable to generate a pump beam (11) for a resonant cavity in which a laser medium (74) is arranged. A beam-shaping waveguide element (18) is arranged between the pump source and the resonant cavity. Shaping of the pump beam is achieved by tailoring the refractive index profile of the waveguide element (18) so that it yields an intensity distribution which spatially overlaps a desired ring-shaped Laguerre-Gaussian mode of the resonant cavity sufficiently well to achieve laser oscillation on said desired Laguerre-Gaussian mode. A ring-shaped or doughnut-shaped laser beam profile can thus be generated. It is further possible to design the refractive index profile (76) so that the pump beam's intensity distribution also spatially overlaps the fundamental mode of the resonant cavity sufficiently well to achieve laser oscillation also on said fundamental mode. The laser will then lase on both the fundamental mode and the selected Laguerre-Gaussian mode. This is useful for producing a variety of beam profiles based on mixing a Gaussian profile with a ring-shaped profile. A top-hat beam profile can be achieved by such mixing.

A diffusive ultraviolet illuminator is provided. The illuminator can include a reflective mirror and a set of ultraviolet radiation sources located within a proximity of the focus point of the reflective mirror. The ultraviolet radiation from the set of ultraviolet radiation sources is directed towards a reflective surface located adjacent to the illuminator. The reflective surface can diffusively reflect at least 30% the ultraviolet radiation and the diffusive ultraviolet radiation can be within at least 40% of Lambertian distribution. A set of optical elements can be located between the illuminator and the reflective surface in order to direct the ultraviolet radiation towards at least 50% of the reflective surface.

An optical fiber including: (i) a silica based, rare earth doped core having a first index of refraction n1; (ii) a silica based inner cladding surrounding the core and having a second index of refraction n2, such that n1>n2, said inner cladding having a plurality of air holes extending longitudinally through the length of said optical fiber; (iii) a silica based outer cladding surrounding said inner cladding and having a third index of refraction n3, such that n2>n3, wherein said optical fiber supports a single polarization mode within the operating wavelength range.

Novel processing methods for production of high-refractive index contrast and low loss optical waveguides are disclosed. In one embodiment, a “channel” waveguide is produced by first depositing a lower cladding material layer with a low refractive index on a base substrate and a refractory metal layer. Then, an etch mask layer is deposited on the refractory layer, followed by selective etching of the refractory metal layer with a dry-etch tool with high selectivity to the etch mask layer. Then, the refractory metal layer is oxidized to form an oxidized refractory metal region, and a top cladding layer made of a second low refractive index material to encapsulate the oxidized refractory metal region. In another embodiment, a “ridge” waveguide is produced by using similar process steps with an added step of depositing a high-refractive-index material layer and an optional optically-transparent layer.

The invention relates to a pohotonic crystal fiber and a pohotonic crystal fiber sensor. The pohotonic crystal fiber comprises a cladding, a fiber core and at least one air hole; the cross section of the air hole is in a sector shape, the arc-shaped face of the air hole is far away from the fiber core, and the inner wall of the air hole is firstly plated with calcium fluoride thin film and then plated with metal nano thin film. The pohotonic crystal fiber sensor is further provided. The pohotonic crystal fiber and the pohotonic crystal fiber sensor have the advantages that the outer diameter of the pohotonic crystal fiber is 125 micrometers, and therefore operation such as coupling and fusing between fibers in an optical network can be quite conveniently achieved. Filling of the metal nano thin film and to-be-detected microfluid is easily achieved through the large diameter of the air hole, selective film plating is not needed in the operation, and the sensing accuracy is guaranteed. The operation process is simple and rapid, and real-time sensing measurement on environmental media can be achieved. A double-layer film plating operation mode is provided, transmission losses of the pohotonic crystal fiber can be effectively reduced, and the sensing stability and the sensing flexibility are improved.

The present invention provides a microstructured hollow-core optical fiber. The optical fiber comprises first type medium circular tubes, second type medium circular tubes, and a third type medium circular tube; the first type medium tubes are nested in the second type medium circular tubes and are periodically distributed along the circumference of the second type medium circular tubes; intervalsbetween the outer walls of the adjacent first type medium circular tubes are greater than 0; the second type medium circular tubes are nested in the third type medium circular tube; and the first type medium circular tubes, the second type medium circular tubes and the third type medium circular tube are connected with one another in a tangent or intersecting manner. According to the microstructured hollow-core optical fiber of the invention, confinement loss can be lowered by simply increasing the number of the second type medium circular tubes, so that a difficulty that the confinement lossof a negative-curvature anti-resonant hollow-core optical fiber cannot be reduced by simply adopting a means of increasing annular layers which assists in reducing the confinement loss of a hollow-core photonic band gap optical fiber can be eliminated. According to the optical fiber provided by the invention, too many nodes will not be introduced into the cross section of the optical fiber, and anew scheme and idea can be provided for the design and manufacture of a broadband low-loss hollow-core optical fiber.

The invention relates to an optical fibre comprising a core and a cladding comprising a core material and a cladding material, respectively, wherein said fibre is a non-linear microstructured optical fibre, said microstructured optical fibre being obtainable by a method comprising loading said core material and optionally said cladding material with hydrogen and / or deuterium whereby the lifetime of the fibre may be extended in high pulse applications.

A metal / dielectric construction having either an optically transmissive substrate adapted for channeling light therethrough, or a dielectric substrate, an optional adhesion-promoting layer composed of an oxide form of at least one metal or metalloid deposited onto the surface of the substrate, a layer composed of a highly reflective and / or electrically conductive / electromagnetic metal overlaying the adhesion-promoting layer, and a protective layer composed of a parylene polymer film formed over the metal layer.

A Fresnel lens-integrated optical fiber that can be easily aligned and manufactured in miniature, and a method of fabricating the same are provided. The Fresnel lens-integrated optical fiber includes a light transmission section transmitting incident light, a light expansion section coupled to the light transmission section and expanding light provided from the light transmission section, and a Fresnel lens surface formed on a section of the light expansion section and focusing by passing through the light expanded in the light expansion section at a predetermined focal length. Accordingly, since the Fresnel lens surface has no curvature, arrangement of an optical coupling system is easy, manufacture is easy, and the optical coupling system can be miniaturized.

An optical fiber for communications systems, the fiber being designed to ensure a compensation of Kerr effects. The fiber has a profile which ensures that changes in power produce changes in distribution of power between core and cladding, such that the phase change associated with the changed spatial distribution of the power, is equal and opposite to the phase change due to Kerr Effect.

The invention provides a step index optical fiber which presents cladding having an index lower than the index of silica and a core with an index higher than the index of silica. The fiber is obtained by drawing a preform made by chemical vapor deposition using a deposition tube of index lower than the index of silica. Inner cladding of index substantially equal to the index of the deposition tube, and then a core of index higher than the index of the inner cladding are deposited in succession therein. The invention makes it possible to obtain a fiber having a large effective area, reduced attenuation, and suitable for being fabricated at low cost by chemical vapor deposition.