The new generation of survey telescopes and future giant observatories such as E-ELT or TMT do not only require very
fast or very large mirrors, but also high sophisticated instruments with the need of large optical materials in outstanding
The huge variety of modern optical materials from SCHOTT covers almost all areas of specification needs of optical
designers. Even if many interesting optical materials are restricted in size and/or quality, there is a variety of optical
materials that can be produced in large sizes, with excellent optical homogeneity, and a low level of stress birefringence.
Some actual examples are high homogeneous N-BK7 blanks with a diameter of up to 1000 mm, CaF2 blanks as large as
300 mm which are useable for IR applications, Fused Silica (LITHOSIL®) with dimensions up to 700 mm which are
used for visible applications, and other optical glasses like FK5, LLF1 and F2 in large formats.
In this presentation the latest inspection results of large optical materials will be presented, showing the advances in
production and measurement technology.