Design of Single-Polarization Photonic Crystal Fiber with Circular Holes for Application to Polarization Splitter

摘要

So far, elliptical-hole core circular-hole holey fibers (EC-CHFs), which can easily achieve single-polarization regime, have been proposed, while elliptical air holes require a high precision fabrication technique. In this research, we propose a novel absolutely single-polarization single-mode (SPSM) photonic crystal fiber (PCF) with only circular air holes based on the same regime of EC-CHF. A double-hole unit is adopted to replace the elliptical-hole which can achieve large birefringence up to the order of 10~(-2) and avoid the challenge to fabricate the elliptical air holes. Moreover, the proposed SPSM-PCF with double-hole unit can be used to compose a cross-talk free polarization splitter (PS) which has a high structural tolerance than that based on EC-CHFs.