Fused silica as an optical material [Invited]

Fused silica glass, with its large transparency range, low thermal expansion, high resistance to optical damage, high refractive index homogeneity, and ease of finishing has found use as an optical material in applications as varied as space shuttle windows, optical fiber, and deep UV lens elements. Its widespread role as an optical material has been enabled by manufacturing the glass from pure liquid precursor compounds, thereby minimizing impurities, and maximizing refractive index homogeneity. As a technical material, silica glass exhibits anomalous properties with respect to volume as a function of temperature and cooling rate, among other properties; these anomalies remain under investigation to this day. This article describes the manufacture of silica glasses and some of their varied optical applications. Silica is often used in demanding environments, an example of which is its use as a lens material for lithography systems using high photon excimer lasers. Static and dynamic properties of silica glass are discussed here.