Crystal Fibre A/s

Nkt Photonics A/s

Technical University of Denmark

Optoceutics Aps

Jes Broeng

Anders Overgaard Bjarklev

Stig Eigil Barkou Libori

Guillaume Vienne

Jacob Riis Folkenberg

Christian Jakobsen

Peter M W Skovgaard

Martin Dybendal Nielsen

Stig Eigil Barkou

Robert C Dobkin

Jens Kristian Lyngsøe

Jesper Bevensee Jensen

Peter Skovgaard

Niels Asger Mortensen

Kim Per Hansen

Jesper Laegsgaard

Anders Petersson

Erik Knudsen

Marcus Carstensen

Paul Michael Petersen

Mark Henney

Ngoc Mai Nguyen

Thomas Sondergaard

Christian Rasmussen

Thorkild Sorensen

Kristian Nielsen

Rene Engel Kristiansen

René Engel Kristiansen

Gamma brain stimulation for preventing or treating Alzheimer's disease or sleeping disorders using light or sound is known. A strobing 40 Hz light source has been shown to cause positive effects due to the stimulation. It is an advantage to know the actual dosage of light that enters the person's eyes in order to understand the relationship between dosage and effectiveness. A camera is used to detect the subject's gaze angle, distance, pupil diameter and any other factors that affect the light power that enters the eye. A target dosage is first determined by a medical worker, such as to determine the effects of the exact same dosage on a group of similar persons, such as Alzheimer's patients. With deviations of gaze angle, distance, and pupil size from the ideal, the effective dosage is decreased. The disclosed system adjusts the actual dosage, such as session duration, based on such factors so that the final dosage received by the person is consistent and meets the target dosage.

Gamma stimulation pulsing light source system with dosage adjustment for gaze angle

The present disclosure relates to system applications of multicore optical fibers. One embodiment relates to a base transceiver station for a wireless telecommunication system comprising a plurality of antenna units arranged in a MIMO configuration and adapted for transmission and/or reception of radio-frequency signals, an optical transmitter in the form of an electro-optic conversion unit for each of said plurality of antenna units, each electro-optic conversion unit adapted for converting an RF signal into an optical signal, a plurality of a single core optical fibers for guiding the optical signals, and at least one first space division multiplexing (SDM) unit adapted for multiplexing said single core optical fibers into respective individual cores of a multicore fiber, or into respective individual modes of a multimode fiber.

Wireless distributed antenna MIMO

The invention relates to a hollow core optical fiber having light guided in a single-mode in the core.

Hollow core fiber with improvements relating to optical properties and its use, method of its production and use thereof

A method of coupling a spliceable optical fiber includes (A) providing the spliceable optical fiber, the spliceable optical fiber including (a) a core region; and (b) a microstructured cladding region. The cladding region surrounds the core region and includes (b1) an inner cladding region having a refractive index formed by inner cladding features arranged in an inner cladding background material with a refractive index n, the inner cladding features including thermally collapsible holes or voids, and (b2) an outer cladding region with an outer cladding background material with a refractive index n, the spliceable optical fiber having at least one end. (B) Collapsing the thermally collapsible holes or voids by heating the at least one end of the spliceable optical fiber thereby increasing the refractive index of the inner cladding providing an expanded core. And, (C) coupling the collapsed spliceable optical fiber end to the optical component.

Splicing and connectorization of photonic crystal fibres

The invention relates to optical fibers for use in optical amplification of light, such as in optical fiber amplifiers and lasers and for use in delivery of high power light, in particular to a scheme for reducing amplified spontaneous emission at undesired wavelengths. The invention further relates to articles, methods and use. An object of the invention is achieved by a micro-structured optical fiber, which is adapted to guide light by the photonic bandgap effect and to have one or more pass bands and at least one stop-band over a wavelength range from &#x3bb;to &#x3bb;. In an aspect of the invention, the at least one stop-band provides filter functions that suppress nonlinear effects. In another aspect, the core region is actively doped, and the active material has an emission spectrum with a higher value of the emission cross section &#x3c3;at a wavelength &#x3bb;between &#x3bb;and &#x3bb;than outside said wavelength range such that amplified spontaneous emission and lasing within the wavelength range from &#x3bb;to &#x3bb;is reduced. In still another aspect, the optical fiber exhibits photonic bandgaps at different wavelength ranges in different radial directions of a cross section of the optical fiber.

Active optical fibers with wavelength-selective filtering mechanism, method of production and their use

An article comprising an optical fiber, the fiber comprising at least one core surrounded by a first outer cladding region, the first outer cladding region being surrounded by a second outer cladding region, the first outer cladding region in the cross-section comprising a number of first outer cladding features having a lower refractive index than any material surrounding the first outer cladding features, wherein for a plurality of said first outer cladding features, the minimum distance between two nearest neighboring first outer cladding features is smaller than 1.0 &#x3bc;m or smaller than an optical wavelength of light guided through the fiber when in use; a method of its production, and use thereof.

Optical fibre with high numerical aperture, method of its production, and use thereof

The present invention relates in general to coupling of light from one or more input waveguides to an output waveguide or output section of a waveguide having other physical dimensions and/or optical properties than the input waveguide or waveguides. The invention relates to an optical component in the form of a photonic crystal fiber for coupling light from one component/system with a given numerical aperture to another component/system with another numerical aperture. The invention further relates to methods of producing the optical component, and articles comprising the optical component, and to the use of the optical component. The invention further relates to an optical component comprising a bundle of input fibers that are tapered and fused together to form an input coupler e.g. for coupling light from several light sources into a single waveguide. The invention still further relates to the control of the spatial extension of a guided mode (e.g. a mode-field diameter) of an optical beam in an optical fiber. The invention relates to a tapered longitudinally extending optical waveguide having a relatively larger cross section that over a certain longitudinal distance is tapered down to a relatively smaller cross section wherein the spatial extent of the guided mode is substantially constant or expanding from the relatively larger to the relatively smaller waveguide cross section. The invention may e.g. be useful in applications such as fiber lasers or amplifiers, where light must be coupled efficiently from pump sources to a double clad fiber.

Optical coupler devices, methods of their production and use

A mircrostructured optical fiber that guides light in a core region, where the fiber has a cladding region that includes a background material and a number of cladding features or elements that are elongated in the longitudinal direction of the fiber and have a higher refractive index than the cladding background material. The core region has a lower effective refractive index than the cladding, and the fiber may guide light in the core by photonic bandgap effects.

Photonic bandgap fibre, and use thereof

A microstructured optical fibre comprising an inner cladding and an outer cladding; said outer cladding comprising elongated outer cladding features extending in an axial direction of the fibre, and at least one cladding recess extending at least partly through the outer cladding in a radial direction to the inner cladding; said cladding recess providing optical access to the inner cladding; a method of forming a cladding recess in such an optical fibre comprising a step of collapsing a part of the outer cladding features by use of a heat source; an apparatus comprising such a microstructured optical fibre, preferably a laser or an amplifier.

Microstructured optical fibre with cladding recess, a method of its production, and apparatus comprising same

An optical fiber for transmitting light, said optical fiber having an axial direction and a cross section perpendicular to said axial direction, said optical fiber comprising: (1) a first core region comprising a first core material having a refractive index N; (2) a microstructured first cladding region surrounding the first core region, said first cladding region comprising a first cladding material and a plurality of spaced apart first cladding features or elements that are elongated in the fiber axial direction and disposed in the first cladding material, said first cladding material having a refractive index Nand each said first cladding feature or element having a refractive index being lower than N, whereby a resultant geometrical index Nge,cl, 1? of the first cladding region is lowered compared to N; (3) a second core region surrounding said first cladding region, said second core region comprising a second core material having a refractive index N, and (4) a second cladding region surrounding the second core region, said second cladding region comprising a second cladding material having a refractive index N, wherein the first core material, the first cladding material and the first cladding features, the second core material, and the second cladding material are selected and arranged so that N&#x3e;N, N&#x3e;N, and N&#x3e;N.

Dual core photonic crystal fibers (PCF) with special dispersion properties

A preform for a microstructured fibre or a part for a preform for a microstructured fibre. The preform or part has a length in the longitudinal direction and a cross section perpendicular thereto, and includes a rod arranged at the centre of the preform or part, with one or more tubes being concentric to the rod. The rod is sleeved inside a first of the concentric tubes, and the rod and/or at least one of the concentric tubes has grooves and/or slits extending in the longitudinal direction, with the number of innermost longitudinally extending grooves and/or slits with respect to a centre of the preform or part being at least six.

Fabrication of microstructured fibres

An optical fibre for transmission of light at a predetermined wavelength, the fibre having a core region, an inner cladding region and an outer cladding region, the inner cladding region having spaced apart voids, at least some of which are at least partly filled with a fluid substance to modify a refractive index in the cross-section of the fibre. The fluid substance may be introduced by preparing and fixing the fibre ends, identifying the voids to be filled and infusing the fluid therein while masking openings in the remaining voids. By selective heating of parts of the fibre, the location of the fluid substance in the void may be controlled to extend over only a fraction of the length of a void that extends the length by the fibre.

Composite material photonic crystal fibres, method of production and its use

An optical wavelength conversion device including a micro-structured optical waveguide, which includes sections with a non-linear material having an index of refraction which changes as a non-linear function of light intensity. The optical waveguide includes a light guiding core region, and is dimensioned for providing spatial overlap between the sections filled with the non-linear material and light propagating within the waveguide. First and second optical light sources may also be included, the second light source having an intensity sufficient to change the refractive index of the non-linear material sufficiently to encode or modulate the light from the first light source through the effect of leaking light from the first light source inside the guiding core to the outside of the guiding core.

Optical wavelength converter

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.

Micro-structured optical fiber

A microstructured optical fiber having a specially designed cladding to provide single mode waveguidance and low sensitivity to bending losses. In one aspect the optical fiber has an inner and an outer cladding each comprising elongated features. The inner cladding features have normalized dimensions in the range from 0.35 to 0.50 and the outer cladding features have normalized dimensions in the range from 0.5 to 0.9, where the normalization factor is a typical feature spacing. The fiber is further characterized by a feature spacing of the inner cladding larger than 2.0 micron. In a second aspect, the fiber has a special non-circular and non-equilateral-polygonial outer cross-sectional shape to mechanically ensure bending in predetermined directions that are favourable with respect to low bending losses. The present invention provides fibers, which are less sensitive to macro-bending losses than presently known single-mode fibers with similar sized mode areas, and provides robust, single-mode, large-mode area fibers for long-distance optical transmission and fibers with special dispersion properties.

Growing community of inventors

Birkerød, Denmark

Jes Broeng