Transparent from deep UV to FIR Excimer laser applications Calcium Fluoride is extremely transparent over a wide spectrum from deep UV (135nm) to far IR.(9.4?m), which is the idal windows for the very short wavelength excimer lasers. The crystal has very low index (about 1.40) and thus elimimating the need of antireflection coatings. It is slightly soluble in water. Diameter: -0.1 Wedge Angle: 3 arc minutes Flatness: l/2 at 633nm Surface Quality: 80-50 scratch-dig Uncoated