Distribution of polarization vector for evanescent optical near-field

Abstract

An analysis with the Fresnel formula is presented as possible ways of creating an elliptically polarized evanescent optical field from a linearly polarized laser beam. Under a certain condition a quadrature phase difference is created while light faces total reflection. It has been observed that there is a translational symmetry of the field normal to the plane of incidence (Y-axis); in this direction the field is always linearly polarized. In the other orthogonal directions the field can be elliptically polarized. Looking normal to the plane of the interface (along the Z-axis), one can see an elliptical polarization with varying ellipticity at various z. A circular polarization is also achievable at some particular combination of angle of polarization vector and angle of incidence.

Keywords:

• evanescent field; circular polarization; zones matrix

Acknowledgement

The author thankfully acknowledges assistance from the Council of Scientific and Industrial Research, Government of India.