Design of cross-talk-free polarization converter based on square-lattice elliptical-hole core circular-hole holey fibers

In this paper, a novel polarization converter (PC) based on square-lattice elliptical-hole core circular-hole holey fibers is proposed and analyzed. The proposed PC has oblique elliptical air holes in the core region, which can achieve polarization rotation with a conversion length as short as 31.7 mu m. Additionally, in order to achieve a cross-talk-free PC element, we propose a PC element with three cores, which can completely convert polarization state by 90 deg. The structural tolerance of the cross-talk-free PC element has also been discussed in detail.