OPTICAL IMAGING ARRANGEMENT

摘要

An optical element arrangement is provided comprising an optical element unit, a first support structure and a reference external to the optical element unit. The optical element unit comprises an optical element group, at least one optical element unit reference associated to the optical element group and a second support structure supporting the optical element group. The optical element group comprises a plurality of optical elements defining an optical axis of the optical element group. The optical element unit reference has a reference position with respect to the external reference. The first support structure supports the optical element unit via a plurality of support elements, the plurality of support elements being arranged to support the optical element unit such that, upon thermal expansion of at least one of the optical element unit and the first support structure, the reference position, at least along the optical axis, remains substantially unchanged.