Design and analysis of a photonic crystal fiber supporting stable transmission of 30 0AM modes

摘要

In this paper, a new circular photonic crystal fiber (PCF) is designed, which can support stable transmission of 30 orbital angular momentum (OAM) modes. It is composed of 4 rings of air holes in the cladding and a large air hole in the center. The numerical results show that the fiber has good features. In the wavelength range of 1.35-1.8 mu m, dispersion variations are less than 27.99 ps/nm/km when the order of OAM mode is less than 6. The confinement losses of most vector modes are lower than 10-8 dB/m at the wavelength of 1.55 mu m. Nonlinear coefficients are below 4.144 W-1/km in the whole bandwidth. In addition, all modes have higher purity and the highest mode purity can reach 99.78%. Moreover, the influence of elliptical deformation on this fiber is also considered. The results indicate that the fiber has good tolerance to elliptical deformation. All these properties show that the designed PCF will play an important role in optical communication systems in the future.