In this video, a change in temperature is applied equally to Aluminum, Ti-64, Invar-36 and ALLVAR Alloy 30. You’ll see the effect temperature changes have on common materials used in optics compared to ALLVAR. Negative Thermal Expansion ALLVAR Alloy 30 maintains focus across a wide temperature range where the other housing materials fail. Create athermal optics that are smaller, lighter, and improve performance across temperature extremes.