Abstract: To compensate for undesirable thermooptical effects in optical pumping of solid-state laser rods, regions of the lateral surface are heated in such a way that reverse thermal gradients are created at these locations. This is achieved by providing said regions with a radiation-absorbing layer which is heated by pump radiation and laser radiation.

Abstract: A laser-active optical fiber for a fiber laser or an optical fiber amplifier contains a laser-active fiber core (2) comprising an undoped inner region (22) which is surrounded by an outer region (24) that is doped with a laser-active material. In this manner a high-power laser beam may be generated which has a mode structure, present in the form of a ring mode, which in particular is suitable for laser machining.

Abstract: A laser-active optical fiber for a fiber laser or an optical fiber amplifier contains a laser-active fiber core (2) comprising an undoped inner region (22) which is surrounded by an outer region (24) that is doped with a laser-active material. In this manner a high-power laser beam may be generated which has a mode structure, present in the form of a ring mode, which in particular is suitable for laser machining.

Abstract: To compensate for undesirable thermooptical effects in optical pumping of solid-state laser rods, regions of the lateral surface are heated in such a way that reverse thermal gradients are created at these locations. This is achieved by providing said regions with a radiation-absorbing layer which is heated by pump radiation and laser radiation.

Abstract: A laser-active optical fiber for a fiber laser or an optical fiber amplifier contains a laser-active fiber core (2) comprising an undoped inner region (22) which is surrounded by an outer region (24) that is doped with a laser-active material. In this manner a high-power laser beam may be generated which has a mode structure, present in the form of a ring mode, which in particular is suitable for laser machining.

Abstract: An intravascular stent or a similar filigree structure is produced in one piece from a cylindrical thin-walled tube. The stent has a plurality of bridges with side faces and apertures delimited by them. At least part of a side face extends obliquely with respect to the outer and inner surface of the stent. The tube is held on a machining apparatus in such a way that it can turn about its central longitudinal axis. The apertures are cut with a laser beam directed at the outer surface of the tube. The remaining wall areas form the bridges. The beam axis of the laser beam is directed toward at least part of the length of a kerf, which has been formed in the tube wall to create an aperture, in such a way that said beam axis hits the outer surface of the tube obliquely.

Abstract: A stable resonator for solid-state lasers which exhibit a thermally induced lensing effect, includes a laser rod, a rear mirror and a semi-reflecting output mirror. The invention is characterized in that the rear mirror has an extremely asymmetrical configuration, allowing the laser rod to move totally or almost totally toward the side of the output mirror. The laser rod is curved in a convex manner on one end in order to achieve a refractive effect, and a convex rear mirror is provided. As a result of the extreme asymmetry, the resonator has a beam quality as a function of the pump power with a comparably flat maximum even at relatively short resonator lengths in contrast to the state of the art. The effects of the thermal lens have practically no influence on processing results. Starting pulse behavior lies below the detection limit.

Abstract: The invention relates to a laser-processing unit, in particular a laser-welding unit, having a laser beam source (2) for generating a laser beam (LS) and having a pivotable focusing unit (8) for pivoting the laser beam (LS) about two axes of rotation (x, y) and for focusing the laser beam (LS) in a focus (F). A dichroic mirror (4) is arranged in the beam path of the laser beam (LS) between the laser beam source (2) and the focusing unit (8), which mirror is assigned an observation device (20) in such a manner that the optical axis (22) of this device coincides with the axis (24) of the laser beam (LS) as it propagates downstream of the dichroic mirror, as seen in the direction of propagation of the laser beam (LS).

Abstract: The invention relates to a laser-processing unit, in particular a laser-welding unit, having a laser beam source (2) for generating a laser beam (LS) and having a pivotable focusing unit (8) for pivoting the laser beam (LS) about two axes of rotation (x, y) and for focusing the laser beam (LS) in a focus (F). A dichroic mirror (4) is arranged in the beam path of the laser beam (LS) between the laser beam source (2) and the focusing unit (8), which mirror is assigned an observation device (20) in such a manner that the optical axis (22) of this device coincides with the axis (24) of the laser beam (LS) as it propagates downstream of the dichroic mirror, as seen in the direction of propagation of the laser beam (LS).

Abstract: In a device for perforating cigarette paper strips, a row of adjacent optical elements (28) is disposed in the ray path of a laser beam deflected by a rotating mirror (12). Each of the optical elements includes a diffractive optical element (DOE) (24'; 24"; 24'") and a convergent lens (18'; 18"; 18'"). A parallel bundle of laser rays hits the surface of the DOE, and the DOE emits one or more bundles of rays with a desired configuration. The convergent lens produces therefrom in the plane of the cigarette paper strip (20) one or more focal spots, for example two or four mutually offset focal spots (22a, 22b) or a ring focus, so that one can form not only microperforations by individual focal spots but also macroperforations by applying energy to only the peripheral area of a macroperforation rather than the entire perforation area.

Abstract: Current supply means for a laser flash lamp contain a fast switch and control means which modulate the amplitude of each individual pulse with a presettable modulating frequency and depth of modulation. This permits higher peak envelope powers to be obtained at an unchanged mean power of the individual pulses so that the necessary threshold values can be better exceeded during materials processing. The amplitude modulation of the individual pulses also prevents undesirable shielding plasma from forming above the processing place.

Abstract: Current supply means for a laser flash lamp contain a fast switch and control means which modulate the amplitude of each individual pulse with a presettable modulating frequency and depth of modulation. This permits higher peak envelope powers to be obtained at an unchanged mean power of the individual pulses so that the necessary threshold values can be better exceeded during materials processing. The amplitude modulation of the individual pulses also prevents undesirable shielding plasma from forming above the processing place.

Abstract: To alleviate the adverse thermal effects of the pumping power and to increase the efficiency of the laser, a solid state laser rod is formed of a polygonal cross-section having flat, internally reflecting side surfaces extending parallel to the rod axis. A light beam applied to one end surface describes an angluar helical path within the rod to a second end surface. By passing the light beam through diverse areas of the rod, compensation for radial temperature gradients is obtained. A plurality of laser beams may traverse the rod.

Abstract: A device for a simultaneous soldering of at least two connecting elements (52) of an electronic structural element (54) on a circuit plate bar (50) comprises a workpiece support (44) and a laser (10) for producing the soldering energy, and has arranged two soldering beams (20) of at least approximately equal intensity, having in their path, at any time, an optic (30) for focusing the soldering beams (20) on the soldering spots. The resonator of the laser (10) is closed on both of its londitudinal sides by a semi-reflecting mirror (12) for production of a relative movement between the soldering beams (20) and the workpiece support (44), there is, at any time, a deflecting device provided, having two by a control device (48) independently adjustable mirrors (38, 40) for an operative deflection of the respective soldering beam (20).

Abstract: Apparatus for optical chopping of a laser beam into discrete light pulses consisting of a source of laser light, a rotating mirror, a first collecting lens located between the laser source and the rotating mirror, a first system of collecting lenses for receiving light reflected from the mirror, and a second system of collecting lenses which receive light from the first system and direct the light energy in a predetermined pattern on the surface of a substrate such as a moving web of paper to be perforated or divided.