Abstract: An apparatus for determining the particle size and/or particle shape of a mixture of particles is provided, comprising a feeding device, which passes the mixture of particles through a zone of measurement as a particle flow; an illumination module, which generates illumination beams and illuminates the zone of measurement with them; a detection module comprising two cameras, each recording an area of the zone of measurement assigned to the respective camera, said cameras recording the areas with different magnifications, and comprising an evaluating module, which determines the particle size and/or particle shape on the basis of the recordings of the cameras, characterized in that the illumination module is provided such that it illuminates the two areas with different intensities.

Abstract: A laser for generating pulsed laser radiation is provided, having a resonator, a laser-active medium, which is situated in the resonator, a Q-switch, which is situated in the resonator, and which can be put into a first state and a second state to set the resonator quality. The resonator quality is lower in the first state than in the second state. The laser also may have a detection unit, which, when the Q-switch is in the second state, measures the intensity of the building laser pulse and outputs it as an intensity signal. The laser may further have a control unit for controlling the Q-switch, which, as a function of a predetermined pulse duration and the applied intensity signal, switches the Q-switch from the second state into the first state, before the pulse buildup of the laser pulse is completed.

Abstract: In a precision mechanical-optical system, there is the problem of guaranteeing, for the production of a composite made from a plurality of mounted optical lenses, the mutual alignment of the optical axes during assembly and high strength of the composite after assembly with low expense in terms of equipment. Flanges are formed on the mounts for the optical elements, these flanges projecting outward in the radial direction and for adjacent mounts, abutting each other with facing joint surfaces, and are clamped by threaded connections tightening in the axial direction between paired, opposing bending elements.

Abstract: In a method for reducing color moiré in digital images, the object is to improve the suppression of color moiré in such a way that effects on edge areas and fine structures are further reduced in that low-frequency beats causing color moiré are detected and attenuated in such a way that correction is carried out only for two-dimensionally extensive areas and the edge areas and fine structures remain excluded to a great extent. A comparison of bandpass energies between the luminance channel and chrominance channels serves as a marking criterion in order initially to determine pixels in which color moiré is present and then to carry out a frequency-selective energy reduction in the chrominance channels at middle frequencies for suppressing the long-wave color moiré.

Abstract: In a method for the production of window elements which can be soldered into a housing in a hermetically tight manner and of a window element sealing a housing, the object of the invention is to achieve an improved hermetic sealing between window and housing through increased adherence and homogeneity in the metal coating and to prevent penetration of scattered light and unwanted radiation. Optically transparent, flat substrate material whose size is sufficient for a plurality of window elements is provided on at least one surface with an optical coating from which frame-like portions on a coated surface which enclose optically active surfaces of the window elements are subsequently removed, whereupon a metal coating that is used for producing a solder connection to the housing is applied to the generated portions having no coating, and the window elements are separated from the substrate material.

Abstract: A laser for generating pulsed laser radiation. An element is arranged in the resonator to generate laser radiation having the first wavelength by frequency conversion of the primary radiation. The resonator is switchable into a first state in which it is open to the primary radiation, and a second state in which it is closed to the primary radiation, and is open to laser radiation of the first wavelength in both states. A control unit switches the resonator from the first to the second state so that the primary radiation begins to oscillate and the pulse generation by frequency conversion begins, switches the resonator from the second to the first state, whereby primary radiation is coupled out from the resonator. It is possible to set the duration between both steps and/or the coupling-out behavior of the resonator to adjust the pulse duration via the control unit.

Abstract: A laser for generating pulsed laser radiation is provided. The laser includes a resonator, a laser-active medium arranged in the resonator, and an acousto-optic modulator arranged in the resonator. The modulator can be put in a first and a second state so as to set the resonator quality, the resonator quality being lower in the first state than in the second state, and comprising a control unit for controlling the modulator. The control unit effects phase-locked coupling of a high-frequency signal to be applied to the modulator in one of said two states, in order to generate a predetermined sound field in the modulator, and a switching signal designed to switch the modulator periodically between the two states.

Abstract: An apparatus for determining the particle size and/or particle shape of a mixture of particles is provided, comprising a feeding device, which passes the mixture of particles through a zone of measurement as a particle flow; an illumination module, which generates illumination beams and illuminates the zone of measurement with them; a detection module comprising two cameras, each recording an area of the zone of measurement assigned to the respective camera, said cameras recording the areas with different magnifications, and comprising an evaluating module, which determines the particle size and/or particle shape on the basis of the recordings of the cameras, characterized in that the illumination module is provided such that it illuminates the two areas with different intensities.

Abstract: A hand-held pulse laser distance measuring device and a pulse reflection mixing method both having an algorithm which controls a microcontroller and which serves to calculate the distance to a measurement object by at least two different time differences ?11, ?12 between a measurement pulse and a reference pulse with a pulse width ?t, which time differences ?11, ?12 are measured with a pulse repetition frequency f1, f2, respectively, wherein a selection module is provided which selects at least the first pulse repetition frequency f1 from at least a first frequency set {f}1 with at least one other pulse repetition frequency f1i in such a way that the condition |?11·f1i|>A >2·|?t11·f1i| is satisfied with a pre-selected lower limit A, a relative time difference |?1i·f1i| and a relative pulse width |?t?·f1i|.

Abstract: The object of a pulsed laser arrangement and a method for adjusting the pulse length of laser pulses is to change the pulse length over a wide range substantially independent from the laser output power, in particular to counteract a reduction in output and to prevent a negative change in the beam parameters when lengthening the pulse by means of varying the oscillator output. A multistage laser amplifier in which an amplifying medium with a small-signal amplification of more than 10 is provided in every stage (17-22) is arranged downstream of a diode-pumped Q-switched solid state laser oscillator with variable oscillator output for supplying oscillator pulses. The total small-signal amplification brought about by all of the amplifying media is greater than 1000. The pulsed laser arrangement and the method can be used for industrial and medical purposes requiring pulse lengths in the range of several hundred ns to several ?s at pulse repetition rates between 10 kHz and 200 kHz.

Abstract: A radiation-transparent die half for a forming die in which a beam outlet from a shaping beam outlet surface is spatially limited by a diaphragm is manufactured in a simpler and more economical manner. Further, a long life is additionally ensured through the possibility of reworking the forming beam outlet surface in combination with effective protection of the diaphragm. According to the invention, the diaphragm is constructed as a radiation-impermeable layer which is enclosed up to its end faces by radiation-transparent material.

Abstract: The object in an arrangement for pumping an anisotropic laser crystal is to reduce the influence of the destruction limit of the laser crystal on increased pump power density and, in this connection, to achieve improved beam quality and increased efficiency of a diode-pumped solid state laser. At the same time, the pump volume and cross-sectional area are to be kept as small as possible along a length of the crystal corresponding at least approximately to the absorption length. The arrangement operates with an asymmetric pump beam whose pump beam cross section has different dimensions perpendicular to one another and with a laser beam cross section which is adapted to this asymmetry. That axis of the crystallographic axes of the anisotropic laser crystal in whose direction the highest value of the crystal breaking limit exists is oriented along the greatest temperature gradient in the direction of the smaller dimension of the pump beam cross section.

Abstract: A diode-pumped laser is disclosed with internal frequency doubling to prevent interfering power fluctuations in the laser radiation generated by the non-linear crystal at the start of the power adjustment in a simple and, therefore, inexpensive construction without power-reducing elements in the cavity or thermal effects having a negative impact on the laser behavior. The laser contains, as laser-active medium, a solid-state laser crystal with a temperature gradient directed substantially parallel to the cavity axis. The conversion of laser radiation of a fundamental laser wavelength into laser radiation of another wavelength is carried out by a non-linear optical crystal with a lower non-linear conversion efficiency than that required for achieving maximum power of the converted laser radiation. The laser can be used particularly for medical purposes, e.g., in the field of ophthalmology for coagulation of the retina as well as in the field of dermatology.

Abstract: In a diode-pumped laser amplifier the inventive object is to increase the tolerance of the amplifier arrangement relative to variations of the input parameters significantly, so that fine-tuning is no longer necessary for guaranteeing the stability of the amplifier. Into a laser-active solid-state medium where a thermal lens of a strength which is different in orthogonal planes is generated in consequence of the irradiated pump radiation, a laser beam to be amplified is directed into the laser-active solid-state medium while being focused in the plane with a strong thermal lens, wherein a beam waist that is being generated lies in the area of the thermal lens. The laser amplifier can be used for amplifying the radiation of an oscillator.

Abstract: A laser range finding device is shown which contains a transmitting channel and a receiving channel. The transmitting channel includes a transmitting lens and a laser light, which is positioned at a focal point of the transmitting lens. The receiving channel includes a receiving lens and a photodiode chip array arranged at a focal point of the receiving lens. The photodiode chip array includes a perforated shutter having at least two shutter apertures.

Abstract: The object in an arrangement for pumping an anisotropic laser crystal is to reduce the influence of the destruction limit of the laser crystal on increased pump power density and, in this connection, to achieve improved beam quality and increased efficiency of a diode-pumped solid state laser. At the same time, the pump volume and cross-sectional area are to be kept as small as possible along a length of the crystal corresponding at least approximately to the absorption length. The arrangement operates with an asymmetric pump beam whose pump beam cross section has different dimensions perpendicular to one another and with a laser beam cross section which is adapted to this asymmetry. That axis of the crystallographic axes of the anisotropic laser crystal in whose direction the highest value of the crystal breaking limit exists is oriented along the greatest temperature gradient in the direction of the smaller dimension of the pump beam cross section.

Abstract: It is the object of a device for converting a fundamental laser frequency to other frequencies to further increase the conversion efficiency in successive nonlinear processes at a low cost with respect to material and alignment and in a space-saving compact arrangement and to make use of the advantages of noncritical phase matching for this purpose. Between two nonlinear optical crystals for generating a first new frequency and for frequency mixing of a pair of laser beams which is generated in the first crystal and whose laser beams are polarized perpendicular to one another, there is arranged another birefringent crystal which is penetrated by the pair of laser beams and in which nonlinear optical characteristics are prevented, so that the pair of laser beams exits from the birefringent crystal with unchanged frequencies.

Abstract: A radially adjustable lens mounting with a mounting ring, a lens and a large number of leaf spring elements each of which is firmly attached to the mounting ring at one end, the other end being in contact with a ring groove formed by the peripheral surface of the lens. The lens mounting allows a frictionless and tilt-free adjustment of the lens and holds the lens in a manner that is stable over a long time and is independent of thermal and mechanical stresses.

Abstract: A radially adjustable lens mounting with a mounting ring, a lens and a large number of leaf spring elements each of which is firmly attached to the mounting ring at one end, the other end being in contact with a ring groove formed by the peripheral surface of the lens. The lens mounting allows a frictionless and tilt-free adjustment of the lens and holds the lens in a manner that is stable over a long time and is independent of thermal and mechanical stresses.