Optical subsystem characterization in laboratory
Résumé
The Bepi Colombo mission will explore the Mercury planet and its environment. Probing of Hermean Exosphere By Ultraviolet Spectroscopy (PHEBUS) is one of the instruments of the payload. It is a double spectrometer for Extreme Ultraviolet (EUV) and Far Ultraviolet (FUV) spectral regions devoted to the characterization of Mercury's exosphere. In this work we will present the calibration philosophy that will be applied to the Flight Model, and explain how a full instrument calibration can be derived from the wholly characterization of the optical subsystems through the Mueller Matrix formalism. The experimental results concerning of PHEBUS prototype optical subsystems are presented, which have been performed in the 55 - 315 nm range by using the normal incidence reflectometer at LUXOR Laboratory (CNR - Institute for Photonics and Nanotechnology, Padova).