A highly birefringent and compact nonlinear photonic crystal fiber for next-generation optical fiber applications: design and investigation

Birefringence is a critical aspect in fiber optic-based applications, particularly in preserving polarization and achieving nonlinear-based phase matching conditions. This study proposes a new highly birefringent nonlinear photonic crystal fiber that is simple and compact. The proposed fiber structure features only six air holes in the cladding to confine light at the core, resulting in a more compact design. The fiber exhibits an observed birefringence of about 0.0113, a nonlinear coefficient of about 86.64 W-1 km(-1), and a confinement loss of about 10(-18) dB/km. The measured V-parameter of about 1.108 ensures single-mode operation of the proposed fiber. The compact design and promising properties of the proposed fiber structure make it suitable for a variety of fiber optic-based applications.