Optical absorption, Faraday rotation and Voigt phase difference in doped Cd 1-x Mn x Te:V and Cd 1-y Hg y Te:Mn, V have been studied. Introducing the V dopant increases the absorption coefficient in tail part of spectra and codoping with Mn leads to its reduction. Faraday rotation spectrum of Cd 1 -x Mn x Te:V has features (change of the sign, large value of the Verdet constant) which are due to spin-spin-exchange interaction and is not affected by the V doping. The Voigt phase difference as a function of wavelength shows similarity to the spectral dependence of the Verdet constant because of their common nature in the studied semimagnetic semiconductors. However, significant enhancement of the Voigt effect was found more as the temperature was decreased.