Investigating the cross core octagonal photonic crystal fiber with high birefringence: A design and analysis study

Abstract

In optical communication systems, the quality of transmitted signals can be compromised by random birefringence, which is caused by irregularities in the core-cladding boundaries. To eliminate this problem, high birefringence can be introduced through an asymmetrical fiber structure. Photonic crystal fibers (PCFs) are an ideal solution due to their high intrinsic index contrast and design flexibility, which allows for high birefringence to be achieved. This paper introduces a new PCF design that takes advantage of these features to provide a higher modal birefringence compared to conventional fibers. The design is a cross-core octagonal-shaped fiber, and its performance is evaluated in terms of birefringence and beat length. The results indicate that the proposed fiber provides a birefringence range of 1.3E-3 to 1.6E-3 for a transmission wavelength range of 1.4 μm to 1.8 μm (S, C, and L Bands) and a minimum beat length range of 1.02 mm to 1.12 mm. This fiber design enables long-haul fiber communication without polarization mode dispersion, even under conditions of external perturbation.