Towards Ultralow Thermal Distortion Glasses For IR And Visible Wavelengths

Compositionally tailored glasses offer potential for ultra low thermal distortion (less than 10-6/°C) optical components at a variety of wavelengths of current interest. Based on existing data, and calculations performed in this work, certain families of phosphate, fluorophosphate, silicate and heavy metal fluoride glasses (HMFG) appear to be promising candidates for ultralow distortion in the near-IR to near-UV range, while HMFG are also promising for mid-IR use. Although some general correlations between properties and composition can be established using existing data, the identification of the best candidates for low distortion will require more detailed studies of the dependence of dn/dT, CTE and stress-optic coefficient on composition.