Aerospace

Ever since the invention of sunglasses at the beginning of the last century, inventors have worked on ways to better protect the eye from the sun's harmful radiation. In 1936, Edwin Land advanced the technology by developing polarized lenses using technology he developed at Polaroid. Polarized lenses remained the state of the art until the 1990s when Teledyne and others began experimenting with optical filters that actually absorbed harmful wavelengths of light rather than merely diverting them from the eye through polarization. Teledyne discovered that one critical elemental layer to this new technology was the element dysprosium, which absorbs light in the yellow-green range. Teledyne turned to American Elements to find a cost effective strategy to thin film depose dysprosium onto an optical substrate.