Athermalized imaging lenses are designed to operate over extreme changes in temperature, whilst minimising the performance changes that often occur with a standard off-the-shelf lens. Because the different materials in a lens expand and contract at different rates, it is important that these factors are considered in the design phase to ensure a lens will remain in focus and provide superior performance throughout its operating temperature range. Developing an athermalized lens design, is especially critical in the infrared (8 – 14 micron) waveband because the coefficient of thermal expansion of most infrared materials is orders of magnitude higher than those of visible glasses, creating large changes in the refractive index.
Read more: https://www.resolveoptics.com/2024/11/athermalized-lenses-offer-wide-temperature-range-operation/