Abstract: A spectrometric instrument comprising: a scanning interferometer having a beamsplitter for dividing incident optical radiation into a reflected beam, following a reflected beam path and a transmitted beam following a transmitted beam path; a monochromatic optical radiation source for launching a reference beam into the interferometer along a first propagation path to be initially incident on a first face of the beamsplitter; an observation optical radiation source for launching a divergent observation beam into the interferometer along a second propagation path to be initially incident on the first face of beamsplitter and overlap the reference beam at the first face; wherein the radiation sources cooperate to generate a first angle between the directions of propagation of the two beams along respective first and second propagation paths when initially and simultaneously incident at the first face which is larger than a divergence half-angle of the observation beam 64.

Abstract: A spectrometric instrument comprising: a scanning interferometer having a beamsplitter for dividing incident optical radiation into a reflected beam, following a reflected beam path and a transmitted beam following a transmitted beam path; a monochromatic optical radiation source for launching a reference beam into the interferometer along a first propagation path to be initially incident on a first face of the beamsplitter; an observation optical radiation source for launching a divergent observation beam into the interferometer along a second propagation path to be initially incident on the first face of beamsplitter and overlap the reference beam at the first face; wherein the radiation sources cooperate to generate a first angle between the directions of propagation of the two beams along respective first and second propagation paths when initially and simultaneously incident at the first face which is larger than a divergence half-angle of the observation beam 64.

Abstract: An analyser is provided comprising a sample chamber for holding a liquid sample containing particles and an ultrasound source acoustically couplable to the sample chamber to supply resonant ultrasound energy for acoustically concentrating particles in the liquid sample in nodal planes established thereby. A probe is also provided which is adapted to supply electromagnetic energy into the sample chamber and to receive the supplied electromagnetic energy from the sample chamber at least during a time at which particles are substantially concentrated in associated nodal planes. The analyser is provided with an analysis unit in operable connection to a detector of the optical probe and is adapted to determine one or both a quantitative and a qualitative property of the liquid sample from the received electromagnetic energy.

Abstract: The invention relates to a device for manipulation of particles (30) in a sample liquid (32) said device comprising a source of ultrasound (16) capable of emitting ultrasound with a given wavelength, an inlet for a sample liquid (2), one or more outlets (4, 5, 6) and a compartment (14), being dimensioned to support a standing ultrasonic wave (40) of said wavelength, characterised in that the device further comprises an inlet for sheath liquid (1, 3) configured to direct a sheath liquid (34) to extend substantially in parallel to an anti-node plane (46) of the ultrasonic standing wave (40) proximate to a sheathed compartment wall. Specifically the device may be used in combination with a particle enumeration device for enumeration of somatic cells in milk.

Abstract: 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 ?m or smaller than an optical wavelength of light guided through the fiber when in use; a method of its production, and use thereof.

Abstract: An optical fiber having an axial direction and a cross section perpendicular to the axial direction, the optical fiber having a first light guiding fiber portion with a cladding region with a plurality of spaced apart cladding voids extending longitudinally in the fiber axial direction and a core region bounded by the cladding region, and a solid light transparent fiber portion having a first end facing the first light guiding fiber portion and a second end forming an end face of the optical fiber. The solid light transparent fiber portion provides a hermetic sealing of the cladding voids of the first light guiding fiber portion. A method of producing such an optical fiber and its use, such as an optical fiber connector and an article having a microstructured optical fiber with hermetically sealed end face, are also included.

Abstract: An optical fibre having an axial direction and a cross section perpendicular to the axial direction, the optical fibre having a first light guiding fibre portion with a cladding region with a plurality of spaced apart cladding voids extending longitudinally in the fibre axial direction and a core region bounded by the cladding region, and a solid light transparent fibre portion having a first end facing the first light guiding fibre portion and a second end forming an end face of the optical fibre. The solid light transparent fibre portion provides a hermetic sealing of the cladding voids of the first light guiding fibre portion. A method of producing such an optical fibre and its use, such as an optical fibre connector and an article having a microstructured optical fibre with hermetically sealed end face, are also included.

Abstract: A photonic crystal fiber includes a core region for propagating light in a longitudinal direction of the fiber, a cladding region surrounding the core region, the cladding region including micro-structural elements extending in the longitudinal direction. The cladding region further includes at least one stress element having a coefficient of thermal expansion ?T,SAP and extending in the longitudinal direction of the photonic crystal fiber, the stress element(s) being located in a cladding background material having a coefficient of thermal expansion ?T,cladback different from ?T,SAP. The location of the at least one stress element relative to the core region and the micro-structural elements and the coefficients of thermal expansion ?T,SAP and ?T,cladback are adapted to provide a stress induced birefringence in the core region of the photonic crystal fiber. An article includes a photonic crystal fiber, a method of manufacturing and the use of a photonic crystal fiber are furthermore provided.

Abstract: An optical fiber having a longitudinal direction and a cross-section perpendicular thereto, said fiber in a cross-section comprising: (a) a core region (11) having a refractive index profile with a highest refractive index nc, and (b) a cladding region comprising cladding features (10) having a center-to-center spacing, ?, and a diameter, d, of around 0.4? or larger, wherein nc, ? and d are adapted such that the fiber exhibits zero dispersion wavelength of a fundamental mode in the wavelength range from 1530 nm to 1640 nm; a method of producing such a fiber; and use of such an optical fiber in e.g. an optical communication system, in an optical fiber laser, in an optical fiber amplifier, in an optical fiber Raman amplifier, in a dispersion compensator, in a dispersion and/or dispersion slope compensator.

Abstract: 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.

Abstract: 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 Nco,1; (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 Ncl,1 and each said first cladding feature or element having a refractive index being lower than Ncl,1, whereby a resultant geometrical index Nge,cl, 1? of the first cladding region is lowered compared to Ncl,1; (3) a second core region surrounding said first cladding region, said second core region comprising a second core material having a refractive index Nco,2, and (4) a second cladding regio

Abstract: 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 &mgr;m or smaller than an optical wavelength of light guided through the fiber when in use; a method of its production, and use thereof.