Index of Refraction change in common chalcogenide glasses due to precision glass molding

Due to changes in the fictive temperature as a result of the precision glass molding process there is an induced change in the index of refraction. This can be on the order of 0.001 in oxide glasses and as high as 0.02 in the chalcogenide glasses. It is important to accurately define the expected index of refraction and the tolerance of it after molding as there may be an impact on the optical design tolerances and system performance. We report on the measured change in index of refraction in common chalcogenide glasses due to the Rochester Precision Optics (RPO) precision glass molding process. We will compare the change in index of refraction between as advertised, as measured, as molded, and we will look at post mold annealing recovery. Utilizing an upgraded M3 refractometer we will be able to measure the index from the visible to the LWIR.