Stable Alloys for Lighter IR Optics

ALLVAR alloys are a new class of metals with a tunable thermal expansion coefficient. Most materials expand at a certain rate when heated, but ALLVAR alloys can be programmed to match other materials’ expansion, not change shape, or even shrink when heated.

Today, optics manufacturers across a wide range of light have a problem. Passive optics defocus with changing temperature. This happens because the lenses change shape with change temperature, which shifts the way that they bend light. Infrared (IR) optics for thermal imaging and night vision are especially susceptible to this defocusing effect.

The current solution is to use a multiple-component stabilizing system. This design increases the optic’s weight, size, and design and manufacturing costs. Optics designers have reached the limit of current materials and engineering technology.

ALLVAR alloys shrink when heated. A single component made of ALLVAR alloys that shrinks when heated can replace the current multi-component stabilizing system and passively compensate for temperature changes. This new material can reduce design and manufacturing costs, and more importantly, optic weight and size.