Optical glass and glass ceramic historical aspects and recent developments: a Schott view

Since the time of Galilei 400 years ago the progress of optical systems was restricted due to the lack of optical glass types with different dispersion properties and due to poor material quality. With the work of Otto Schott, which started 125 years ago, glass became a tailorable, highly reproducible and homogeneous material, thus enabling systematic design of optical systems. The demand for new glass types is still going on as well as the requirement for ever tighter tolerances and their proofs. New measurement methods provide deeper insight in the material properties. Developments in processing allow new optical elements to be designed, further advancing technology. This also holds for zero-expansion glass ceramics, another key enabling material for optical systems. This publication highlights some milestones in the history of optical glass and glass ceramics, comments on present day glass development as well as new optical elements and measurement methods and provides some new information on the materials’ properties.