Abstract: The invention relates to a laser (1) for emitting laser light in the visible spectral range. A rare earth doped anisotropic crystal (2) comprising a 5d-4f transition is arranged within a laser resonator (7, 8), and a pumping light source (3) pumps the crystal (2) for generating laser light in the visible spectral range by using the 5d-4f transition. The 5d-4f transition of the rare earth doped anisotropic crystal comprises an absorption band extending over several nm. Thus, pump light having a wavelength within a relatively broad wavelength range can be used. This reduces the requirements with respect to the wavelength accuracy of the pumping light source and, thus, more pumping light sources of an amount of produced pumping light sources can be used for assembling the laser, thereby reducing the amount of rejects.

Abstract: The invention relates to a method of making Ce3+ containing laser materials with a fast cooling rate.

Abstract: The invention relates to a laser (1) for emitting laser light in the visible spectral range. A rare earth doped anisotropic crystal (2) comprising a 5d-4f transition is arranged within a laser resonator (7, 8), and a pumping light source (3) pumps the crystal (2) for generating laser light in the visible spectral range by using the 5d-4f transition. The 5d-4f transition of the rare earth doped anisotropic crystal comprises an absorption band extending over several nm. Thus, pump light having a wavelength within a relatively broad wavelength range can be used. This reduces the requirements with respect to the wavelength accuracy of the pumping light source and, thus, more pumping light sources of an amount of produced pumping light sources can be used for assembling the laser, thereby reducing the amount of rejects.

Abstract: The optical elements for ultraviolet radiation, especially for microlithography, are made from cubic granet, cubic spinel, cubic perovskite and/or cubic M(II)- as well as M(IV)-oxides. The optical elements are made from suitable crystals of Y3Al5O12, Lu3Al5O12, Ca3Al2Si3O12, K2NaAlF6, K2NaScF6, K2LiAlF6 and/or Na3Al2Li3F12, (Mg, Zn)Al2O4, CaAl2O4, CaB2O4 and/or LiAl5O8, BaZrO3 and/or CaCeO3. A front lens used in immersion optics for microlithography at wavelengths under 200 nm is an example of a preferred optical element of the present invention.

Abstract: The optical elements for ultraviolet radiation, especially for microlithography, are made from cubic granatite, cubic spinel, cubic perovskite and/or cubic M(II)- as well as M(IV)-oxides. The optical elements are made from suitable crystals of Y3Al5O12, Lu3Al5O12, Ca3Al2Si3O12, K2NaAlF6, K2NaScF6, K2LiAlF6 and/or Na3Al2Li3F12, (Mg, Zn)Al2O4, CaAl2O4, CaB2O4 and/or LiAl5O8, BaZrO3 and/or CaCeO3. A front lens used in immersion optics for microlithography at wavelengths under 200 nm is an example of a preferred optical element of the present invention.

Abstract: A planar optical apparatus for setting the chromatic dispersion in an optical system, which apparatus has: a waveguide input structure with a first free-beam region, a first phase grating, connected to the first free-beam region, for spatially separating the spectral components of a signal, a second free-beam region, connected to the first phase grating, an optical element for spatially dependent modification of the phase of the spatially separated spectral components in the second free-beam region, a second phase grating, connected to the second free-beam region, for combining the spectral components, with their phase modified, and a waveguide output structure with a third free-beam region. In this case, the optical element for spatially dependent modification of the phase of the spatially separated spectral components includes a first phase plate that can be displaced in the second free-beam region.

Abstract: A planar optical apparatus for setting the chromatic dispersion in an optical system, which apparatus has: a waveguide input structure with a first free-beam region, a first phase grating, connected to the first free-beam region, for spatially separating the spectral components of a signal, a second free-beam region, connected to the first phase grating, an optical element for spatially dependent modification of the phase of the spatially separated spectral components in the second free-beam region, a second phase grating, connected to the second free-beam region, for combining the spectral components, with their phase modified, and a waveguide output structure with a third free-beam region. In this case, the optical element for spatially dependent modification of the phase of the spatially separated spectral components includes a first phase plate that can be displaced in the second free-beam region.

Abstract: An optical waveguide has a core, wherein the core is doped with laser-active ions, and also additionally doped with Ce.

Abstract: An optical waveguide has a core, wherein the core is doped with laser-active ions, and also additionally doped with Cer.

Abstract: A sintered rhenium crucible, highly suitable for growing single crystals from refractory metal oxides, for example by the Czochralski technique, is formed of fine rhenium powder, by sintering. A compact is formed by cold isostatic pressing and thereafter the compact is sintered at 500-2800.degree. C. to obtain a sintered crucible. Product density is limited to 88-95% of theroretical in order to maximize creep resistance.

Abstract: In a semiconductor element is shown having a silicon layer, a waveguide comprising silicon and a diode structure connected with external, conductive contacts. The diode structure is provided in such an arrangement to the waveguide that the diode structure can be influenced by electron hole pairs generated by photons in the waveguide. In order to create a semiconductor element with an optical waveguide and an integrated diode structure, in which high losses in the optical waveguide are avoided, the waveguide is weakly doped, and a germanium-rich layer is a component of the diode structure. The semiconductor element is well suited as a component in integrated optics for optical-electrical conversion.

Abstract: Method for measuring absolute rotation with the aid of a light conductive fiber ring interferometer including a light source, a beam dividing arrangement, a light path formed by a light conductive fiber coil, an optical phase modulator which is disposed in the light path and which modulates the light circulating in the light path with a periodic, optical phase modulation at a fundamental frequency f.sub.0, and a photodetector for providing an electrical output signal. The light circulating in the light path or an electrical output signal from the photodetector is modulated with at least one mixing frequency f.sub.2 in a manner such that an electrical evaluation signal results which has an evaluation frequency f.sub.1 which is smaller than that of the fundamental frequency f.sub.0 and which is evaluated to determine the absolute rotation of interest.

Abstract: A ring interferometer comprises a light source, an optical beam splitting device for receiving light from the light source, a light path encircling an area at least once and opening at both ends into the optical beam splitting device and a photodetector for detecting light from the light path. The light which enters the light path and is coupled to the optical beam splitting device at both ends passes through the light path in both directions. The light then reunites in the beam splitting device and thereby is brought into interference which is detected by the photodetector. The light source is chosen to produce light which has a coherence time which is substantially shorter than the propagation time of light through the light path.

Abstract: A semi-conductor laser comprising a crystal having a sequence of layers forming a heterostructure diode and which includes a laser active zone interposed between a pair of semiconductor layers. Each of these semi-conductor layers has a band gap which is greater than that of the layers within the laser active zone. The laser active zone includes a first semiconductor layer having a given band gap, and at least second and third semiconductor layers each having a band gap which is greater than that of the first layer. The first layer is contiguous with and interposed between semiconductor layers each having a band gap which is greater than that of said first layer and forms a pn-junction with one of those contiguous layers. A strip-shaped region of a uniform conductivity type diffused from the surface of the crystal penetrates into at least one layer of the laser active zone but does not penetrate into the first layer.