Investigation into instrumental polarization of LSVT

The paper deals with determination of the Mueller matrix polarization at the Large Solar Vacuum Telescope (LSVT). Application of large mosaic polarization analysers and a quarter-wave plate (760 mm in diameter) allows us to determine the complete polarization matrix for the entire aperture, including elements from the last column that are necessary in order to take into account the effect of the telescope on circular polarization parameter V. Polarization matrices for the entire objective of the telescope and for its central part are presented. The complete telescope matrix should be taken as derived in the first approximation; a more accurate experiment is required in order to use it for observations.