Abstract: The high-purity alkaline earth halide crystals, especially CaF2, BaF2 or MgF2 crystals, have a diffuse scatter distribution function value of less than 7×10?7, an RMS uniformity of refractive index of less than 15×10?8 after subtraction of Zernike coefficients and an RMS value of birefringence in the (111) direction of less than 0.2 nm/cm. Preferably the crystals exhibit a loss coefficient of less than 5×10?4 cm?1 after irradiation with 10×109 laser pulses with an energy density of 10 mJ/cm2 at a wavelength of 193 nm. Also they have RMS birefringence in the (100) direction or the (111) direction that is less than 0.35 nm/cm.

Abstract: A method for producing high-purity, large-volume monocrystals that are especially radiation-resistant and have low intrinsic birefringence. From a melt of crystalline raw material, with controlled cooling and solidification, a crystal is generated. As the crystalline raw material, shards and/or waste from already-grown crystals is used, and the re-used raw material 1) upon visual observation in daylight has no color; and 2) upon illumination with a white-light lamp in a darkroom a) has no or at maximum a just barely perceivable reddish and/or bluish fluorescence; and b) has no or at maximum a just barely perceivable diffuse scattering; and c) has no or only slight discrete scattering of at maximum two visually perceivable scattering centers per dm3. In this way, crystals can be obtained which after tempering have a BSDF value of <7×10?7, an RMS homogeneity after the subtraction of 36 Zernike coefficients of <15×10?8, an SDR-RMS value in the 111 direction of <0.2 nm/cm.

Abstract: A method for producing high-purity, large-volume monocrystals that are especially radiation-resistant and have low intrinsic birefringence. From a melt of crystalline raw material, with controlled cooling and solidification, a crystal is generated. As the crystalline raw material, shards and/or waste from already-grown crystals is used, and the re-used raw material 1) upon visual observation in daylight has no color; and 2) upon illumination with a white-light lamp in a darkroom a) has no or at maximum a just barely perceivable reddish and/or bluish fluorescence; and b) has no or at maximum a just barely perceivable diffuse scattering; and c) has no or only slight discrete scattering of at maximum two visually perceivable scattering centers per dm3. In this way, crystals can be obtained which after tempering have a BSDF value of <7×10?7, an RMS homogeneity after the subtraction of 36 Zernike coefficients of <15×10?8, an SDR-RMS value in the 111 direction of <0.2 nm/cm.

Abstract: The method for making a uniform, large-size single crystal of calcium fluoride includes placing a single precursor crystal of calcium fluoride in a tempering vessel provided with a cover; introducing calcium fluoride powder into the tempering vessel and subsequently heating the single precursor crystal, preferably in intimate contact with the calcium fluoride powder, in the tempering vessel together with the calcium fluoride powder for two or more hours at temperatures above 1150° C. to temper the precursor crystal and thus form the uniform, large-scale single crystal of calcium fluoride. The uniform large-sized single crystals of calcium fluoride can be used to make improved lens, prism, light-conducting rod, optical window or other optical component for DUV photolithography, steppers, excimer lasers, wafers, computer chips and electronic devices containing the wafers and chips.

Abstract: The method for making a uniform, large-size single crystal of calcium fluoride includes placing a single precursor crystal of calcium fluoride in a tempering vessel provided with a cover; introducing calcium fluoride powder into the tempering vessel and subsequently heating the single precursor crystal, preferably in intimate contact with the calcium fluoride powder, in the tempering vessel together with the calcium fluoride powder for two or more hours at temperatures above 1150° C. to temper the precursor crystal and thus form the uniform, large-scale single crystal of calcium fluoride. The uniform large-sized single crystals of calcium fluoride can be used to make improved lens, prism, light-conducting rod, optical window or other optical component for DUV photolithography, steppers, excimer lasers, wafers, computer chips and electronic devices containing the wafers and chips.