Design of a Photonic Crystal Fiber for Dispersion Compensation and Sensing Applications Using Modified Air Holes of the Cladding

High birefringence and high negative dispersion with minimum confinement loss of an octagonal photonic crystal fiber is proposed using modified air holes of the cladding. This analysis indicates that the proposed photonic crystal fiber design near to square air holes provides higher 0.245 birefringence and higher − 722.48 ps/(nm × km) negative dispersion with confinement loss of 0.117 dB/km at 1.55-μm wavelength. The obtained results like birefringence and negative dispersion are high in proposed octagonal photonic crystal fiber in comparison with circular air hole–based octagonal photonic crystal fiber. Further, the proposed photonic crystal fiber is utilized for ethanol sensing, and it is observed that relative sensitivity and confinement loss are 16.97% and 4.97 × 10⁻³ dB/km, respectively. Hence, the proposed fiber is best suitable for application in dispersion compensation, polarization-maintaining, and sensing. Such fiber structure can easily be designed by slightly changing the structural parameter during fiber drawing.