Investigation of a new kind of high birefringence photonic crystal fiber

Abstract

A kind of highly birefringent and highly nonlinear photonic crystal fiber (PCF) is proposed. The fundamental mode field, birefrin-gence, nonlinear coefficient, effective mode area and dispersion characteristic of the fiber are studied by the full-vector finite elementmethod. Simulation results show that the birefringence becomes larger by reducing the air hole pitch, and the birefringence reachesup to 10-2 at a wavelength of 1550 nm, which is about two orders of magnitude higher than that of the regular elliptic polarizationmaintaining fiber. At the same time, a nonlinear coefficient of 42 W-1·km-1 is obtained. There are two zero dispersion wavelengthsin the visible and the near-infrared region respectively, and flattened chromatic dispersion from 800 nm to 2000 nm is obtained. Sucha design provides a new approach to obtaining highly birefringent and highly nonlinear PCF, and the fiber has a broad prospect ofapplication in the polarization control, nonlinear optics and dispersion control.