<title>High-frequency gratings as polarization elements</title>

Abstract

ABSTRACT Binary gratings with feature sizes smaller than the illumination wavelength were fabricated in quartz glass by means ofmicrostructuring techniques. Using rigorous coupled wave analysis polarization elements like polarizing beam splitters and phase retardation plates were designed for operation in transmission at the wavelength of 650 nm. High frequencypolarization gratings with feature sizes down to 140 mu and aspect ratios up to 7 were realized. For the polarizationselective beam splitting elements we measured diffraction efficiencies of about 80 % in the -l order for TE polarisation,and 90 % in the O order for TM polarization. The values are in good agreement with the theoretical values. Furthermore werealized phase retarding elements e.g. ?/8-p1ates which showed a phase difference of 1 = 44,8° (theor. 45°) between TEand TM polarized light.The design and the fabrication process as well as the optical properties of our high frequency binary phase gratings will bepresented. Experimental results will be compared with theoretical values.Keywords: Diffractive polarization beam splitters, zero-order gratings, polarization selective elements, high frequencygratings, binary gratings, diffractive optical elements, micro-fabrication, binary phase retarders, diffractivephase elements.