Method to traceably determine the refractive index by measuring the angle of minimum deviation

Abstract The refractive index (RI) of a solid depends on the illumination wavelength, temperature and material properties, such as chemical composition, crystal structure, isotropy. RI measurements, however, also depend environmental conditions, temperature, pressure, CO 2 concentration humidity surrounding air. As these conditions are not always reported, reported values often irreproducible. Here we describe new optical set-up based angle minimum deviation to traceably measure at controlled humidity, Advantages method that (I) perform measurements without need for an independent measurement prism angles, (II) correlations in uncertainty propagation reduce sensitivity coefficients greatly. absolute fused silica 20.00 °C is 1.470 091 404.66 nm, 1.467 169 435.83 1.460 459 546.07 1.459 237 579.07 nm. expanded ( k = 2) procedure 1.4 × 10 ?6 nm 1.7 main factors affecting calibration rotary stage, repeatability measurement.