Abstract:
Aditya-L1, India’s first mission with multiple science payloads is designed to study the solar
dynamics. Aditya-L1 includes multiple payloads, the significant one being the Visible Emission
Line Coronagraph (VELC). VELC is designed to study the solar corona from 1.05 Ro to 3R, which
has never been achieved by any other space solar mission. It consists of four channels for
observation, two spectroscopic, one spectropolarimetric and one imaging channel.
VELC contains 38 optical elements including mirrors, lenses, diffraction grating, etc. These 38
optical elements are made into 17 optical assemblies. The performance of each of the elements
must be tested and calibrated before they can be used in the payload. This report will go through
all the procedures followed for calibration of polarization modulators, polarizing beam displacers
and diffraction grating.
