Abstract: Optical fibre based measurement system having a system for generating radiation (Z) with monotonically tuneable wavelength during sweep periods, an optical path (T) and a detector (D) connected to the system for generating radiation (Z) via the optical path (T). The optical path (T) comprises the interferometer (I) comprising the multi-port element (EW) and the attached measuring optical fibre (F) sensitive to at least two environmental parameters, the mode excitation system (P) adapted for excitation in the measuring optical fibre (F) of at least the measuring mode (Mnl) with the first effective refractive index and the measuring mode (Mn2) with the second effective refractive index, having different sensitivity to these two parameters. The measurement system comprises the processing unit (UP) to which the detector (D) is connected via the analogue-to-digital converter (ADC), and the processing unit (UP) is adapted to generate the control signal for the system for generating radiation (Z).

Abstract: A microstructured multicore optical fibre (MMOF) includes a cladding in which a plurality of basic cells are formed that run along the MMOF. Each of the basic cells includes a core, and at least one of the basic cells is surrounded by a plurality of longitudinal areas that run parallel to the core along the MMOF and are arranged in a hexagonal arrangement around the core. The longitudinal areas are spaced by a lattice constant ?. Sides of the hexagon can be shared with adjacent basic cells.

Abstract: Disclosed is an interferometric fiber optic sensor for detecting chemical substances. A light source a detector are connected to a light dividing element in an optical path with an optical fiber segment. The optical fiber segment is further optically coupled with a measuring element across a residual cavity. The measuring element further has a face adapted to be exposed to a test substance that may contain a chemical substance to be detected. The optical fiber segment and the measuring element can be held together so that there is only the residual cavity between them. The optical fiber segment is contained, at least along part of its length, within a capillary. A first end part of the capillary is joined with the measuring element while another portion of the capillary is joined or clenched on the optical fiber segment, so that the capillary, the optical fiber segment and the measuring element together form a fiber optic measuring probe as a part of the optical path with the light source and detector.

Abstract: A fibre-optic measurement system equipped with a controlled light generation system (1) and a receiving system (2) connected via an optical path which comprises a directional device (4) and which, in addition, has a processing unit (9) for controlling the light generation system (1) and for receiving and processing the signal from the receiving system (2), according to the invention, it is characterized by the fact that it has a selective mode device (5) and is adapted to be connected to a fibre-optic telecommunications network by a selective mode device (5) and the processing unit (9) is adapted to implement the OFDR and/or COTDR measurement technique for measuring changes in the optical distance and processing them into one or more parameters. Moreover, the object of the invention is also the method of adaptation of a telecommunications network into a sensor network and a fibre-optic measurement and communication system.

Abstract: A microstructured multicore optical fibre (MMOF) includes a cladding in which a plurality of basic cells are formed that run along the MMOF. Each of the basic cells includes a core, and at least one of the basic cells is surrounded by a plurality of longitudinal areas that run parallel to the core along the MMOF and are arranged in a hexagonal arrangement around the core. The longitudinal areas are spaced by a lattice constant ?. Sides of the hexagon can be shared with adjacent basic cells.

Abstract: Microstructured multicore optical fibre with a microstructure area, in which, at least two basic cells are embedded, where each of them contains a core, preferably made of glass, specifically including doped silica glass or polymer, together with the surrounding it longitudinal areas with lower refraction index vs. that of the cladding, which areas may adopt the shape of holes, filled with gas, in particular with the air or a fluid or a polymer or spaces of another glass with doping allowing to reduce refractive index (further referred to as holes), embedded in a matrix of glass, in particular of silica glass or polymer. The refraction index of the holes is decreased vs. that of the matrix of glass, in particular of silica glass or polymer. The basic cell is characterised by the diameter of D2 core, the diameter of D3 core and the distance between adjacent holes, corresponding to lattice constant A.

Abstract: A temperature monitoring device containing a control system adapted to generate substantially periodic control waveforms applied to the control input of the light source with tunable wavelength connected to an optical fiber interferometer, in which a measuring optical fiber is connected in one its arms, and the interferometer output is connected to a detector whose output is connected to a signal processing module adapted to identify temperature changes in the optical fiber length function, in accordance with the invention, characterized in that the light source coherence length is longer than 0.5 m, and the period of the periodic waveform is shorter than or equal to 20 s, the difference between the minimum and maximum wavelength is higher than 3 ?m, and the optical fiber is adapted to its placement near exoenergetic devices in a vehicle, during its operation.

Abstract: Disclosed is an interferometric fiber optic sensor for detecting chemical substances. A light source a detector are connected to a light dividing element in an optical path with an optical fiber segment. The optical fiber segment is further optically coupled with a measuring element across a residual cavity. The measuring element further has a face adapted to be exposed to a test substance that may contain a chemical substance to be detected. The optical fiber segment and the measuring element can be held together so that there is only the residual cavity between them. The optical fiber segment is contained, at least along part of its length, within a capillary. A first end part of the capillary is joined with the measuring element while another portion of the capillary is joined or clenched on the optical fiber segment, so that the capillary, the optical fiber segment and the measuring element together form a fiber optic measuring probe as a part of the optical path with the light source and detector.

Abstract: A waveguide interferometer includes a multicore fiber used a multicore waveguide, where the multicore waveguide includes a coupler section formed by tapering a portion of the multicore waveguide so that one core though which a light source is fed is optically coupled to another core that is terminated differently that the core into which the source signal is provided. The terminations respond differently upon being exposed to an environmental condition or substance, and the difference in response to the environmental condition or substance results in a shift in interference of the light reflected back through the multicore waveguide, which is detected with a detector on the same side of the multicore waveguide as the light source.

Abstract: A device for measuring the parameters of phase elements and dispersion of optical fibers, characterized in that it contains: a light source, serially connected to fiber optic coupler, one of whose arms constitutes a part of the reference arm, and whose second arm constitutes a part of the measurement arm of the device, and a motorized linear stage is mounted on the arm of the device. One of the arms of the device is connected to at least one detector, and at least one collimator is placed in at least of the arms of the device, at least before the phase element. A method of measuring the parameters of the phase element and the dispersion of optical fibers is conducted in two stages, wherein the first stage assumes the calibration of the device and the second stage is the proper measurement.

Abstract: A waveguide interferometer includes a multicore fiber used a multicore waveguide, where the multicore waveguide includes a coupler section formed by tapering a portion of the multicore waveguide so that one core though which a light source is fed is optically coupled to another core that is terminated differently that the core into which the source signal is provided. The terminations respond differently upon being exposed to an environmental condition or substance, and the difference in response to the environmental condition or substance results in a shift in interference of the light reflected back through the multicore waveguide, which is detected with a detector on the same side of the multicore waveguide as the light source.

Abstract: A device for selectively increasing higher-order mode losses comprises an optical fiber taper executed on a multi-mode fiber of a selected wavelength, and the fiber taper has separated regions, i.e. non-tapered fiber regions which have a first diameter equal to that of the main fiber. The tapered regions can also include transition regions in which the fiber diameter is reduced/increased, respectively, and a taper waist region which has a reduced diameter, where the taper level ratio between the regular diameter and the narrowed diameter is at least 20%, and the length of the transition regions are at least 0.5 mm on one side and may be zero on the other side, and the length of the taper waist with the narrower diameter is at least 0.5 mm. Furthermore, the taper area is coated with a filtering substance with attenuating properties between the tapered section and the cladding.

Abstract: Microstructured optical fibre with selectively enlarged spaces of reduced refraction index, especially for the generation of non-linear effects and stress measurements with a ring configuration of spaces, located around a cladded core, where the spaces demonstrate cross-section shape close to circle and decreased diffraction index, especially for the generation of non-linear effects and stress measurements, made of glass, preferably of silica glass or polymer and are located in nodes of hexagonal lattice with distances between the lattice nodes equal to the lattice constant, in which, around a single-mode core, there are, at least two rings with spaces of decreased diffraction index, filled with gas or fluid or a polymer, where the diameter of every-second space with decreased diffraction index in, at least, one ring, is enlarged to be lower from the double lattice constant, while the diameters D of all the enlarged spaces with decreased diffraction index are similar in size and the diameters d of non enlarge

Abstract: Microstructured multicore optical fibre with a microstructure area, in which, at least two basic cells are embedded, where each of them contains a core, preferably made of glass, specifically including doped silica glass or polymer, together with the surrounding it longitudinal areas with lower refraction index vs. that of the cladding, which areas may adopt the shape of holes, filled with gas, in particular with the air or a fluid or a polymer or spaces of another glass with doping allowing to reduce refractive index (further referred to as holes), embedded in a matrix of glass, in particular of silica glass or polymer. The refraction index of the holes is decreased vs. that of the matrix of glass, in particular of silica glass or polymer. The basic cell is characterised by the diameter of D2 core, the diameter of D3 core and the distance between adjacent holes, corresponding to lattice constant A.

Abstract: A method of connecting optical fibers coated with conductive layer, preferably metalized, with metal elements, comprising the following stages: 1. preparing the electrolyte, 2. clearing the optical fiber surface and clearing the electrodes, 3. placing the optical fiber and the metal sensor element in the electrolyzer, 4. enabling flow of electricity, 5. cleaning the elements—the optical fiber element bonded to the metal element.

Abstract: Fibre coupler for creation of optical fibre-containing interferometers (sensors), with at least two parallel optical fibres placed in an enclosure characterized in that each of the optical fibres consists of at least three alternately placed light-conductive sections with different coatings, at least one (1) of which has a melting point above 200° C., and the two corresponding sections (2) with coating other than with a melting point above 200° C. are coupled using any known method. Interferometer containing above described fibre couplers, where the fibre couplers are interconnected by at least two optical fibre sections (8, 9) with a high temperature-resistant coating.

Abstract: Fiber structure including a core and a cladding, a central microstructure having a first plurality of longitudinal holes and which is adapted for guiding optical radiation and for birefringence in the core. Also included is a side microstructure having a second plurality of longitudinal holes is provided, wherein the side microstructure partly surrounds the central microstructure and provides a predetermined mechanical anisotropy, a pressure responsive unit for converting an isotropic pressure force to birefringence changes on the core, a lateral force responsive unit for converting a directional pressure force to birefringence changes on the core, a temperature responsive unit for converting temperature to birefringence changes on the core, and a birefringence responsive unit for converting birefringence in the core to wavelength information.

Abstract: Fiber structure including a core and a cladding, a central microstructure having a first plurality of longitudinal holes and which is adapted for guiding optical radiation and for birefringence in the core. Also included is a side microstructure having a second plurality of longitudinal holes is provided, wherein the side microstructure partly surrounds the central microstructure and provides a predetermined mechanical anisotropy, a pressure responsive unit for converting an isotropic pressure force to birefringence changes on the core, a lateral force responsive unit for converting a directional pressure force to birefringence changes on the core, a temperature responsive unit for converting temperature to birefringence changes on the core, and a birefringence responsive unit for converting birefringence in the core to wavelength information.

Abstract: A microstructured fiber or photonic crystal fiber is described having a doped solid core region and a cladding region, holes being provided in the cladding region, the fiber having a low hybrid splice loss to conventional fiber as well as being able to be tightly bent due to the microstructured cladding. The cladding region can contain a plurality of holes surrounding and distanced from the core. These holes are preferably located symmetrically around the core and extend longitudinally along the length of fiber. The holes may be two or more D-shaped holes or truncated D-shaped holes arranged symmetrically around the care. In other embodiments, the holes comprise hole structures arranged symmetrically around the core in a ring. The holes may be arranged having the inner side facing the core formed from arcs of a circle, e.g. equal arcs of a circle. Between the arcs circular holes may be provided called capillaries, i.e. smaller holes.

Abstract: Fiber structure including a core and a cladding, a central microstructure having a first plurality of longitudinal holes and which is adapted for guiding optical radiation and for birefringence in the core. Also included is a side microstructure having a second plurality of longitudinal holes is provided, wherein the side microstructure partly surrounds the central microstructure and provides a predetermined mechanical anisotropy, a pressure responsive unit for converting an isotropic pressure force to birefringence changes on the core, a lateral force responsive unit for converting a directional pressure force to birefringence changes on the core, a temperature responsive unit for converting temperature to birefringence changes on the core, and a birefringence responsive unit for converting birefringence in the core to wavelength information.