ABSOLUTE REFRACTIVE-INDEXES AND THERMAL COEFFICIENTS OF FUSED-SILICA AND CALCIUM-FLUORIDE NEAR 193 NM

The refractive indices of several fused silica and calcium fluoride sa mples from different suppliers were measured with the minimum deviatio n method in the deep UV between 191 and 196 nm with a standard uncerta inty of 7 ppm. For both materials the dispersion dn/d lambda near 193 nm and 20 degrees C was determined. In addition, we measured the therm al coefficients of the refractive index near 193 nm and between 15 and 25 degrees C.