Design and realization of a high quality large beam collimator

More Info
expand_more

Abstract

With PLATO the European Space Agency (ESA) will launch its third medium-class mission in its Cosmic Vision program. The PLATO satellite consists of 26 optical refractive telescopes where 24 identical wide field cameras form composed images.

Each individual camera must be tested and characterized before being integrated in the satellite. At SRON (Netherlands Institute for Space Research) a thermal vacuum (TV) test facility will mimic the operating conditions of the camera during flight while a star will be simulated by a collimated beam filling the full entrance pupil of the camera.

The aim of this project is to design, build and validate a 150 mm diameter collimator with a λ/4 wavefront error at 700 nm to be used in the PLATO camera thermal vacuum (TV) test facility at SRON.

A requirement breakdown has been made to further determine the collimator design parameters. Multiple design concepts have been generated for distinct parts of the collimator. After choosing the final concepts, a detailed opto- echatranical design has been made. In parallel, an alignment procedure was developed.

The designed components have been manufactured, assembled, aligned, and validated. Result after final alignment is a of λ/5.2 wavefront error at 700 nm over a 150 mm diameter beam, well within the requirement for optical performance.

As the final step of the integration, the collimator has been installed in the TV test facility at SRON where it is now fully operational.