Development of lead-free zero stress optic glass

Glass used in the optical components of large scale image projection must possess a variety of properties, including high transparency, high index of refraction, good durability, and zero stress-optic response. Zero stress-optic response refers to the property of exhibiting no birefringence, and hence no image distortion, even under uneven stress loads. Commercial glass formulations with this property have high lead content, and thus are forbidden by new environmental regulations. We have recently solved the problem of how to identify suitable replacements for lead and still retain zero stress optic response. In the present project we seek to optimize our prototype glasses with respect to transparency, index of refraction, and spectral response. The outcome of this work will be environmentally safe glasses with properties as good or better than current products, which we then hope to develop in collaboration with a Canadian industrial partner.