Abstract: The invention relates to an arrangement for producing a Bessel beam (5), comprising a beam-forming element (2), which transforms a beam (1) incident as a plane electromagnetic wave into a Bessel beam (5). According to the invention, the beam-forming element (2) comprises at least one annular lens (3, 3?) and a Fourier optical unit, e.g. in the form of a Fourier lens (4).

Abstract: The invention relates to an arrangement for producing a Bessel beam (5), comprising a beam-forming element (2), which transforms a beam (1) incident as a plane electromagnetic wave into a Bessel beam (5). According to the invention, the beam-forming element (2) comprises at least one annular lens (3, 3?) and a Fourier optical unit, e.g. in the form of a Fourier lens (4).

Abstract: A device for contactless optical distance measurement includes a polychromatic light source, a light analysis unit and a measurement head. The measurement head has an aperture opening and an optical lens system, which has a chromatic longitudinal aberration. The optical lens system includes a first refractive lens element and a second refractive lens element. At least one of the refractive lens elements has at least one aspherical lens surface, and the first refractive lens element and/or the second refractive lens element has an optical material with an Abbe number 20<=Vd<=41. The optical lens system has such a chromatic longitudinal aberration that a measurement region, which equals an axial focal shift of the optical lens system between the wavelengths of 450 nm and 700 nm, is between 0.2 mm inclusive and 10 mm inclusive.

Abstract: A device for contactless optical distance measurement includes a polychromatic light source, a light analysis unit and a measurement head. The measurement head has an aperture opening and an optical lens system, which has a chromatic longitudinal aberration. The optical lens system includes a first refractive lens element and a second refractive lens element. At least one of the refractive lens elements has at least one aspherical lens surface, and the first refractive lens element and/or the second refractive lens element has an optical material with an Abbe number 20?V d?41. The optical lens system has such a chromatic longitudinal aberration that a measurement region, which equals an axial focal shift of the optical lens system between the wavelengths of 450 nm and 700 nm, is between 0.2 mm inclusive and 10 mm inclusive.

Abstract: The invention is directed to a method for determining the image quality of an optical imaging system and to the use of the method according to the invention for determining the influence of samples on the amplitude distribution and phase front distribution of the illumination light, of which the amplitude distribution is known in particular.

Abstract: Point scanning Laser Scanning Microscope with an element arranged in or near a pupil plane of the beam path between the probe and detection for separation of illumination and detection beams, which element comprises a reflecting or transmitting first region for the transmission of the illumination beam and a transmitting or reflecting second region, lying essentially outside the first region, for the transmission of the probe light, whereby advantageously manipulating devices for the variation of the size and/or the form of the first and/or second region are provided and a method for the adjustment of the microscope with the element wherein the manipulation of the manipulating devices takes place by means of a control circuit.

Abstract: The invention is directed to a method for determining the image quality of an optical imaging system and to the use of the method according to the invention for determining the influence of samples on the amplitude distribution and phase front distribution of the illumination light, of which the amplitude distribution is known in particular.

Abstract: A polymer of the invention comprising the comonomers ethylene, one or more alpha-olefins having 3 to 20 carbon atoms, and one or more cyclic dienes having up to 30 carbon atoms, said polymer having a density of at least 0.890 gram per cubic centimeter; long chain branching; a plurality of double bonds; an Mw/Mn ratio ratio (PDI) of at least 2.5; a flow activation energy of greater than about 6.5 kcal/mol; and a Relaxation Spectrum Index (RSI), PDI, and Melt Index (MI), such that RSI·MIa>2.7 and RSI·MIa·PDIb is in the range of about 0.8 to about 60, when a and b are about 0.6 and minus 1.2, respectively.

Abstract: Curable polymer compositions comprising a crosslinkable polymeric component; an initiator component; and an allyl compound component.

Abstract: A composition comprising: (a) polyethylene; (b) as a scorch inhibitor, alpha-tocopherol in an amount of at least about 0.08 part by weight per 100 parts by weight of polyethylene; (c) optionally, a cure booster; and (d) an organic peroxide.

Abstract: A composition comprising: (a) polyethylene; (b) as a scorch inhibitor, [1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione]; and (c) an organic peroxide.

Abstract: A composition comprising:(a) polyethylene;(b) as a scorch inhibitor, 1,1-diphenylethylene, substituted or unsubstituted;(c) optionally, a cure booster; and(d) an organic peroxide.

Abstract: An axially optically pumped laser 11 is penetrated coaxially by a target beam .lambda..sub.2. This penetration of the pumped laser occurs via light conductor 2 by means of laser diode 31. The pumped laser 11 can be an erbium--YAG laser. For this purpose, the dispersion, diffraction and reflection of an incoupling optic 12, of laser 11 and a focusing device 13 are suitably matched to each other in order that the pump light .lambda..sub.3, work beam .lambda..sub.1 and target beam .lambda..sub.2 are suitably guided and are suitable for small diameters. The laser arrangement is suitable as a medical device for ears, nose and throat and eyes and can be utilized with an endoscope.

Abstract: A cable comprising one or more electrical conductors or a core of one or more electrical conductors, each conductor or core being surrounded by an insulating composition comprising a mixture of(i) about 20 to about 50 percent by weight of a homogeneous polyethylene having a polydispersity in the range of about 1.5 to about 3.5 and an essentially uniform comonomer distribution; and(ii) about 50 to about 80 percent by weight of a homopolymer of ethylene made by a high pressure process.

Abstract: An ethylene polymer having a Polydispersity Index of at least about 3.0, a melt index, MI, and a Relaxation Spectrum Index, RSI, such that (RSI)(MI.sup..alpha.) is greater than about 26 when .alpha. is about 0.7, and a Crystallizable Chain Length Distribution Index, L.sub.w /L.sub.n, less than about 3 is provided. Such ethylene polymer has processability equivalent or superior to even conventional high pressure polyethylene at similar melt index, yet need not be made under high pressure reaction conditions.

Abstract: A cable comprising one or more electrical conductors or a core of one or more electrical conductors, each conductor or core being surrounded by a layer of insulation comprising a multimodal copolymer of ethylene and one or more alpha-olefins, each alpha-olefin having 3 to 8 carbon atoms, the copolymer having a broad comonomer distribution as measured by TREF with a value for the percent of copolymer, which elutes out at a temperature of greater than 90 degrees C., of greater than about 5 percent; a WTGR value of less than about 20 percent; a melt index in the range of about 0.1 to about 30 grams per 10 minutes; and a density in the range of 0.880 to 0.950 gram per cubic centimeter, and being prepared by a low pressure process.

Abstract: An apparatus for laser machining by creating a plurality of discrete and separate beams which are sent to a deflecting device including a support and a plurality of individual elements that act independently and are individually controlled to machine different points on the workpiece simultaneously.

Abstract: For defined ablation of a surface, successive partial regions of equal surface area are acted on by a radiation source, preferably a laser, through an optical system. The partial regions are smaller as regards surface area than the whole surface to be processed, so that the respective radiation source can be dimensioned in a less costly manner. Telescope optics with conical surfaces serve as optical systems suitable for this purpose.

Abstract: An improved slab-waveguide CO.sub.2 laser which includes two parallel, rectangular, flat, spaced-apart, slab electrodes whose surfaces excite a laser gas and guide laser light in a plane perpendicular to the surfaces of the slab electrodes. The component of the light propagating parallel to the electrode surfaces is not guided and is acted on only by resonator mirrors which form an unstable resonator. The improved slab-waveguide CO.sub.2 laser operates on a single vibrational transition of the CO.sub.2 molecule by employing wavelength selective optics.

Abstract: The reflecting surfaces within the resonator are minimized in an unstable laser resonator having a radially-dependent output end reflection profile and a passive Q-switch so that the least possible competing resonator geometries can be formed. For this purpose, a saturable absorber foil can be provided as a passive Q-switch element mounted so as to be inclined with respect to the optical axis. Furthermore, it is advantageous to use an output reflector having highly precise parallel boundary surfaces and to align this output reflector with high precision parallel to the end surfaces which delimit the laser medium.