Abstract: The present invention relates to a surveying apparatus for surveying an object as well as a surveying system comprising the surveying apparatus having a simple and compact optical setup. The surveying apparatus comprises a lens arrangement including at least one movably arranged focus lens element for focusing to sight an object; an imaging unit configured to obtain an image of at least a part of the object; a distance measuring unit configured to measure a distance to the object along the optical axis of the distance measuring unit; and a beam splitter/combiner configured to combine a part of the optical imaging path of the imaging unit and a part of the optical distance measuring path of the distance measuring unit so that the optical axis of the imaging unit and the optical axis of the distance measuring unit are at least coaxially arranged with the optical axis of the lens arrangement between the lens arrangement and the beam splitter/combiner.

Abstract: A surveying system, comprises a support; a rotating mirror unit including a mounting structure, a motor mounted on the mounting structure and having a shaft rotatable about a first axis, and a mirror mounted on the shaft; a measuring unit including a mounting structure and a light source and optics mounted on the mounting structure for directing a beam of measuring light onto the mirror surface; and a window mechanically connecting the mounting structure of the measuring unit and the mounting structure of the rotating mirror unit.

Abstract: A surveying system, comprises a support; a rotating mirror unit including a mounting structure, a motor mounted on the mounting structure and having a shaft rotatable about a first axis, and a mirror mounted on the shaft; a measuring unit including a mounting structure and a light source and optics mounted on the mounting structure for directing a beam of measuring light onto the mirror surface; and a window mechanically connecting the mounting structure of the measuring unit and the mounting structure of the rotating mirror unit.

Abstract: The present invention relates to a surveying apparatus for surveying an object as well as a surveying system comprising the surveying apparatus having a simple and compact optical setup. The surveying apparatus comprises a lens arrangement including at least one movably arranged focus lens element for focusing to sight an object; an imaging unit configured to obtain an image of at least a part of the object; a distance measuring unit configured to measure a distance to the object along the optical axis of the distance measuring unit; and a beam splitter/combiner configured to combine a part of the optical imaging path of the imaging unit and a part of the optical distance measuring path of the distance measuring unit so that the optical axis of the imaging unit and the optical axis of the distance measuring unit are at least coaxially arranged with the optical axis of the lens arrangement between the lens arrangement and the beam splitter/combiner.

Abstract: Optical system for tracking and visually examining a target, comprising an image sensor and a lens arrangement having a variable position relative to the image sensor to project an image of the target onto the image sensor, a light source for emitting light in a predetermined wavelength range in the direction of the target and a filter switch for switching an optical filter for selectively allowing the light in the predetermined wavelength range to pass through to the image sensor into and out of the optical path to optionally perform a visual examination and monitoring of the tracking. A tracking device is provided to perform the tracking of the target using the reflected light in the predetermined wavelength range in a sequence of images held by the image sensor when the first optical filter is switched into the optical path.

Abstract: Reflective target for surveying instruments having a plurality of planar reflective sections arranged to form a shape having a target axis. Each reflective section includes a plurality of prisms, each prism constituted by a corner cube having three surfaces oriented perpendicular to one another and forming a base for receiving incident light, and each of the prisms is oriented such that a common edge formed by two of the three surfaces of the prism is oriented such that the common edge and the target axis or a line parallel to the target axis lie in a common plane.

Abstract: Reflective target for surveying instruments having a plurality of planar reflective sections arranged to form a shape having a target axis. Each reflective section includes a plurality of prisms, each prism constituted by a corner cube having three surfaces oriented perpendicular to one another and forming a base for receiving incident light, and each of the prisms is oriented such that a common edge formed by two of the three surfaces of the prism is oriented such that the common edge and the target axis or a line parallel to the target axis lie in a common plane.

Abstract: Optical system for tracking and visually examining a target, comprising an image sensor and a lens arrangement having a variable position relative to the image sensor to project an image of the target onto the image sensor, a light source for emitting light in a predetermined wavelength range in the direction of the target and a filter switch for switching an optical filter for selectively allowing the light in the predetermined wavelength range to pass through to the image sensor into and out of the optical path to optionally perform a visual examination and monitoring of the tracking. A tracking device is provided to perform the tracking of the target using the reflected light in the predetermined wavelength range in a sequence of images held by the image sensor when the first optical filter is switched into the optical path.

Abstract: A process and a device is described to avoid the depolarization of linear-polarized light during the transmission of light through crystals exhibiting a {111} or {100} crystal plane, respectively, and a <100> or <111> crystal axis, respectively. The device is characterized in that the linear-polarized light meets the surface of the crystals in an angle of 45-75°, whereby the surface is formed by the {111} or the {100} plane. The crystal is arranged in such a way that upon entering the crystal, the light spreads along the <100> or <111> crystal axis, respectively, as parallel as possible, and/or that the device comprises a unit for temperature equalization to avoid a thermal gradient in the crystal.

Abstract: The apparatus for extending or lengthening a laser pulse has a beam splitter. An incident laser pulse is split by the beam splitter into at least one first partial pulse and a second partial pulse. The first partial pulse is conducted through a delaying travel path section with a number of reflectors. The apparatus is characterized by a plurality of the variable delaying travel path sections which produce different length laser beam pulses from a single incident laser pulse.

Abstract: A method of selecting suitable laser-stable optical material for making an optical element, especially for transmission at wavelengths under 200 nm, is described. It includes a first pre-irradiation to produce radiation damage, subsequent excitation of induced fluorescence with light at between 350 to 700 nm at least ten minutes after the first pre-irradiation and measurement of induced fluorescence intensities at one or more wavelengths between 550 nm and 810 nm. After the fluorescence intensity measurement a second pre-irradiation is performed with an at least 1000-fold higher energy than in the first pre-irradiation and then induced fluorescence intensities are again measured to determine the increase in the fluorescence intensities.

Abstract: The method determines laser stability of an optical material, which is suitable for making an optical element through which high-energy light passes. The method includes pre-irradiation to produce radiation damage and measurement of the resulting induced non-intrinsic fluorescence. The method is distinguished by excitation of induced fluorescence immediately after pre-irradiation and after at least ten minutes after pre-irradiation with light of a wavelength between 350 and 810 nm, and measurement and quantitative evaluation of fluorescence intensities at wavelengths between 550 nm and 810 nm. Especially laser-stable optical materials, particularly CaF2 crystals, have a normalized difference (Z) of the fluorescence intensities measured at a first time immediately after pre-irradiation and at a second time at least ten minutes after the pre-irradiation, as calculated by the following equation (1): Z=(I2,?1,?2?I1,?1,?2)I2,?1,?2??(1), which is less than 0.3.

Abstract: The apparatus for extending or lengthening a laser pulse has a beam splitter. An incident laser pulse is split by the beam splitter into at least one first partial pulse and a second partial pulse. The first partial pulse is conducted through a delaying travel path section with a number of reflectors. The apparatus is characterized by a plurality of the variable delaying travel path sections which produce different length laser beam pulses from a single incident laser pulse.

Abstract: A process and a device is described to avoid the depolarization of linear-polarized light during the transmission of light through crystals exhibiting a {111} or {100} crystal plane, respectively, and a <100> or <111> crystal axis, respectively. The device is characterized in that the linear-polarized light meets the surface of the crystals in an angle of 45-75°, whereby the surface is formed by the {111} or the {100} plane. The crystal is arranged in such a way that upon entering the crystal, the light spreads along the <100> or <111> crystal axis, respectively, as parallel as possible, and/or that the device comprises a unit for temperature equalization to avoid a thermal gradient in the crystal.

Abstract: The method determines laser stability of an optical material, which is suitable for making an optical element through which high-energy light passes. The method includes pre-irradiation to produce radiation damage and measurement of the resulting induced non-intrinsic fluorescence. The method is distinguished by excitation of induced fluorescence immediately after pre-irradiation and after at least ten minutes after pre-irradiation with light of a wavelength between 350 and 810 nm, and measurement and quantitative evaluation of fluorescence intensities at wavelengths between 550 nm and 810 nm. Especially laser-stable optical materials, particularly CaF2 crystals, have a normalized difference (Z) of the fluorescence intensities measured at a first time immediately after pre-irradiation and at a second time at least ten minutes after the pre-irradiation, as calculated by the following equation (1): Z=(I2,?1,?2?I1,?1,?2)I2,?1,?2, ??(1) which is less than 0.3.

Abstract: The present invention refers to a method for the quantitative measurement of the pulse laser stability of synthetic fused silica, whereby this method avoids time-consuming and demanding measurements and saves material. First, the absorption of fused silica is measured for different energy densities, and a non-linear function ?1(H) is determined on the basis of the measured values. Second, the fused silica is subject to radiation with a higher energy density up to the point at which a constant absorption value is achieved. In the following, the absorption of the fused silica is measured at different energy densities, and a non-linear function ?2(H) is determined. The difference between the two non-linear functions indicates the increase of absorption that depends on the energy density.

Abstract: The invention relates to a synthetic quartz glass that can be produced by direct precipitation by means of flame hydrolysis of a silicon precursor, especially a chlorine-containing silicon precursor, which quartz glass when irradiated with laser pulses at a wavelength of 193 nm at an energy density (H) of up to H=1.5 mJ/cm2 and at a repetition frequency of the laser pulses of up to R=4 kHz is characterized by the following properties: in the range of energy densities of up to 1.5 mJ/cm2, the equilibrium absorption of quartz glass rises sublinearly with the energy density for all repetition frequencies of the laser pulses; the dependency of the equilibrium absorption on the repetition frequency of the laser pulses is sublinear; and the relationship of equilibrium absorption and energy density (H) can be described as a function of H1.7; the H2 content being at least 0.2·1018 molecules/cm3. Other aspects of the invention relate to a process for producing such a synthetic quartz glass.

Abstract: The present invention refers to a method for the quantitative measurement of the pulse laser stability of synthetic silica glass, whereby this method avoids time-consuming and demanding measurements and saves material. First, the absorption of silica glass is measured for different energy densities, and a non-linear function ?1 (H) is determined on the basis of the measured values. Second, the silica glass is subject to radiation with a higher energy density up to the point at which a constant absorption value is achieved. In the following, the absorption of the silica glass is measured at different energy densities, and a non-linear function ?2 (H) is determined. The difference between the two non-linear functions indicates the increase of absorption that depends on the energy density.