When Experience Matters (part 1)

It was a major challenge in coating: With a diameter of 520 mm and a weight of each 35 kg, the two shown optics were guest stars in our giant IBS machine ‘Teresa‘. Thanks to Prof. Christian Schwab / Macquarie University of Sydney / Australia and to KU Leuven / Belgium for this interesting coating task. 

The optics have been deposited to become broadband high reflectors from 380-950nm. It looks like a metal coating, but is fully dielectric (>85 layers) for best spectral performance, leading to a better signal for the planned application compared to a silver or alumina coating. A special focus was on a flattened but still superior reflectivity profile. With a notably curved surface of the optics, both coating design and Teresa were optimized to reduce distribution effects.

These broadband mirrors are used in an astrophotonic spectrograph setup, that shall discover earth-like planets, i.e. other habitable worlds by detecting resonant light.