Abstract: A laser is disclosed, which is suitable for efficient generation of continuous-wave laser light having a wavelength of about 400 nm or less. The short-wavelength light is generated by first frequency-doubling a fundamental wave, and then sum-frequency mixing the frequency-doubled wave and the fundamental wave. The non-linear interactions are effected by means of quasi-phasematching structures inside a resonant cavity where the fundamental wave is circulating. The sum-frequency mixing is effected using second or higher order quasi-phasematching, which allows for wider domains to be inverted for the quasi-phasematching structure compared to first order quasi-phasematching. Preferably, the sum-frequency mixing is effected using periodically poled stoichiometric lithium tantalate (PPSLT) for second or third order quasi-phasematching.

Abstract: A method in connection with coating, comprising a running web (8) arranged to be coated with a coating mix (11), coating means (1) arranged in connection with said web (8), a coating surface (6, 7) at the coating means (1) and arranged in contact with said web (8) to dose said coating mix (11), and said coating means (1) being provided with at least a first coating surface (6) and a second coating surface (7), in such a way that it is possible at said running web (8) to switch between the one (6) and the other (7) surfaces while at least one of said surfaces (6, 7) is in an active contact position.

Abstract: A dosing device for the application of a coating mix (6) onto a running web, in particular a paper or paperboard web (1), which device comprises a rod (8) that is supported revolvingly over its entire length in a rod cradle (12), and a pressing device (13) acting on the rod cradle and producing a pressure of the rod onto the web (1) and onto the holding-on device (2, 17, 15) of the web, the rod (8) being provided with a wear resistant surface coating (15) with a hardness of about 10 to about 100 according to Shore A. The invention also relates to methods of using said rod, and to said revolving rod.

Abstract: The present invention relates to a method in connection with the manufacturing of a dosing roller, comprising the provision of a roller body (1) with an envelope surface (IA) on which a wire (4) is being wound such that plurality of turns of wire is formed in contact with the envelope surface (IA) and with adjoining turns of wire (4, 4?, 4?) in tight contact with each other, wherein for at least the major part of said adjoining turns of wire (4, 4?, 4?) the surface of the wire (4) which is outwardly exposed is being provided with protrusions (11) and depressions (12).

Abstract: A laser arrangement is provided, in which a Lyot filter arrangement is operative to effect single mode operation. The birefringent element of the Lyot filter arrangement has a cavity folding mirror on one side thereof and a polarizing element on another side thereof, such that the free spectral range of the Lyot filter is improved. Preferably, the Lyot filter arrangement and the laser gain material are located in different branches of the folded cavity.

Abstract: A laser arrangement is provided, in which a Lyot filter arrangement is operative to effect single mode operation. The birefringent element of the Lyot filter arrangement has a cavity folding mirror on one side thereof and a polarizing element on another side thereof, such that the free spectral range of the Lyot filter is improved. Preferably, the Lyot filter arrangement and the laser gain material are located in different branches of the folded cavity.

Abstract: A laser arrangement comprising a first and a second resonant cavity for generating a first and a second fundamental wavelength. A first and a second non-linear region are provided in the second cavity for sum-frequency mixing of the radiation generated in the first cavity and in the second cavity, and for frequency-doubling of the radiation generated in the second cavity, respectively.

Abstract: A laser is disclosed, which is suitable for efficient generation of continuous-wave laser light having a wavelength of about 400 nm or less. The short-wavelength light is generated by first frequency-doubling a fundamental wave, and then sum-frequency mixing the frequency-doubled wave and the fundamental wave. The non-linear interactions are effected by means of quasi-phasematching structures inside a resonant cavity where the fundamental wave is circulating. The sum-frequency mixing is effected using second or higher order quasi-phasematching, which allows for wider domains to be inverted for the quasi-phasematching structure compared to first order quasi-phasematching. Preferably, the sum-frequency mixing is effected using periodically poled stoichiometric lithium tantalate (PPSLT) for second or third order quasi-phasematching.

Abstract: A dielectric based antenna provides for relatively wide band communications. In this regard, the dielectric based antenna may provide communications across a variety of mobile telephone communication types and frequencies, such as GSM850, EGSM900, DCS1800, PCS1900, and UMTS. In one embodiment, the dielectric based antenna includes a dielectric element and at least first and second antenna elements. The dielectric element may be configured into a volumetric shape from a material with a relatively high permittivity. The first and second antenna elements are respectively wrapped about first and second portions of the dielectric element and may provide for respective first and second frequency bands of the dielectric based antenna. An antenna feed port couples the dielectric based antenna to a communication module via an antenna feed such that radio signals may be transmitted and/or received through the dielectric based antenna.

Abstract: A method of generating coherent radiation, wherein a first fundamental beam of radiation from a four level laser and a second fundamental beam of radiation from a three level laser are mixed in a non-linear body to obtain an output beam at the sum frequency of the two fundamental beams. The invention also relates to an arrangement for carrying out the method.

Abstract: A laser arrangement comprising a first and a second resonant cavity for generating a first and a second fundamental wavelength. A first and a second non-linear region are provided in the second cavity for sum-frequency mixing of the radiation generated in the first cavity and in the second cavity, and for frequency-doubling of the radiation generated in the second cavity, respectively.

Abstract: A method and a device for generating visible coherent radiation is disclosed. The visible coherent radiation is generated by sum-frequency mixing of a first fundamental beam from a diode laser and a second fundamental beam from a diode-pumped solid-state laser. The mixing is performed by means of a quasi-phasematching element provided within the resonant cavity of the solid-state laser. The first fundamental beam is stabilized by providing feedback to the diode laser.

Abstract: A method and a device for generating visible coherent radiation is disclosed. The visible coherent radiation is generated by sum-frequency mixing of a first fundamental beam from a diode laser and a second fundamental beam from a diode-pumped solid-state laser. The mixing is performed by means of a quasi-phasematching element provided within the resonant cavity of the solid-state laser. The first fundamental beam is stabilized by providing feedback to the diode laser.

Abstract: A lens arrangement for transforming a divergent, generally astigmatic laser beam from a diode laser into a beam having a high degree of rotational symmetry is disclosed. The arrangement comprises, in series, a first cylindrical gradient index lens arranged with its principal axes parallel to the principal axes of the astigmatic laser beam; a second cylindrical gradient index lens arranged with its principal axes parallel to the principal axes of the astigmatic laser beam; and a third cylindrical gradient index lens arranged with its principal axes rotated 45 degrees with respect to the principal axes of the astigmatic laser beam. The first and the second gradient index lenses have such refractive powers that both the fast and the slow axis of the astigmatic laser beam are converged to a focus inside the third gradient index lens.

Abstract: A method for processing a time domain reflectometry (TDR) signal used to determine at least one process variable for a material in a tank, wherein said TDR signal has been generated by a radar level gauge system comprising a pulse generator, a probe extending into the tank for guiding the pulse, and a receiver for receiving said TDR signal, and wherein the TDR signal comprises at least a surface reflection pulse caused by an interface between different materials in the tank, and an interfering pulse caused by a transition between the pulse generator and the probe.

Abstract: A method for processing a time domain reflectometry (TDR) signal used to determine at least one process variable for a material in a tank, wherein said TDR signal has been generated by a radar level gauge system comprising a pulse generator, a probe extending into the tank for guiding the pulse, and a receiver for receiving said TDR signal, and wherein the TDR signal comprises at least a surface reflection pulse caused by an interface between different materials in the tank, and an interfering pulse caused by a transition between the pulse generator and the probe.

Abstract: A lens arrangement for transforming a divergent, generally astigmatic laser beam from a diode laser into a beam having a high degree of rotational symmetry is disclosed. The arrangement comprises, in series, a first cylindrical gradient index lens arranged with its principal axes parallel to the principal axes of the astigmatic laser beam; a second cylindrical gradient index lens arranged with its principal axes parallel to the principal axes of the astigmatic laser beam; and a third cylindrical gradient index lens arranged with its principal axes rotated 45 degrees with respect to the principal axes of the astigmatic laser beam. The first and the second gradient index lenses have such refractive powers that both the fast and the slow axis of the astigmatic laser beam are converged to a focus inside the third gradient index lens.

Abstract: A method for producing and testing a fiber bed, includes a housing, a main inlet passage and a main outlet passage, a cavity in the housing in fluid connection with the inlet and outlet passages, a body rotatably arranged in the cavity, the body being arranged with a through-going passage having first and a second opening, a screen arranged in the through-going passage, and elements for measuring properties of the fiber bed. The method includes positioning the body so that the first opening is connected to the main inlet and the second opening is connected to the main outlet, creating a first passage, leading a fiber suspension through the first passage in order to produce a fiber bed on the screen, measuring the properties of the bed, rotating the body such that the second opening is connected to the main inlet and the first opening is connected to the main outlet and creating a flow through the first passage for removing the fiber bed from the screen through the outlet.

Abstract: When a running web (3) is coated with a liquid coating mixture, at least one side of the web is provided with a coating (40, 40?) of coating mixture. Existing excess (33) of coating mixture in or adjacent to the regions of the edge portions of the web is removed by being blown off downstreams of where the coating operation is performed.

Abstract: A method of generating coherent radiation wherein a first fundamental beam of radiation from a four level laser and a second fundamental beam of radiation from a three level laser are mixed in a non-linear body, to obtain an output beam at the sum frequency of the two fundamental beams. The invention also relates to an arrangement for carrying out the method.