Question

The incident light is polarized linearly with the azimuth of oscillations, which equals +45º. Can it be transformed into the light, polarized by the right circle, by single reflection?

Answer 1

Linearly polarized light is the sum of two circular polarizations. In order to get one circular polarization, the second one must be suppressed. Only one linear polarization can be suppressed by reflection (reflection at Brewster angle), thus, it can't be transformed into light, polarized by the right circle, by single reflection. A circle can be got only after running through quarter-wave plate.