Question

If circularly polarised light passed through quarter wave plate ,the outcome wave is

Answer 1

A waveplate is a birefringent crystal. Birefringence is a particular kind of anisotropy where the refractive index depends on the plane of polarization of the light: there are two, orthogonal linear polarization planes which have a relatively lower ("fast axis") and higher ("slow axis") refractive index. An waveplate of angle is of such a thickness that the phase delay differs for these two polarization states by as light passes through the crystal.