Application of metallic subwavelength gratings for polarization devices

E-beam lithography offers the possibility for fabricating metallic subwavelength gratings for visible light which show strong polarization properties. By using such gratings and other microoptical elements (like lenses and diffraction gratings) a new kind of polarization detector without mechanical motion is proposed. The basic idea is the use of a special analyzing grating element with different grating directions (e.g. a circular metallic subwavelength grating). We realized both a wavelength-independent polarimeter and a polarimeter with spectroscopic properties. Characteristic parameters estimated are the angular resolution of the polarization plane (best value 0.001 degrees) and the wavelength resolution (best value 15 nm).