Digital Controller for Capacitance Stabilized Etalons

Fabry Pérot Interferometers in Capacitance Stabilized Etalon configuration are a key technology to obtain the physical properties of the solar plasma and the embedded magnetic fields at different heights in the solar atmosphere. This kind of data are fundamental both for synoptic programs and high spatial resolution new generation solar telescopes to understand the still unsolved mechanisms beneath space weather events such as solar flares and CMEs. In this paper we describe a new electronic controller for Capacitance Stabilized Etalons, based on digital approach. The controller allows digital filtering of the signal for higher stability as well as the possibility to switch operation mode as needed in the different phases of the scan and in different observing strategies.