Design of a Polarization-Maintaining Equiangular Spiral Photonic Crystal Fiber for Residual Dispersion Compensation Over $E{+}S{+}C{+}L{+}U$ Wavelength Bands

An equiangular spiral photonic crystal fiber has been designed and numerically optimized to obtain its residual chromatic dispersion compensation property in the wavelength range of 1350–1675 nm. The results show that the fiber exhibits an average dispersion of
${-}{\rm 227}~{\rm ps}/{\rm nm}\hbox{-}{\rm km}$
with a flattened dispersion profile. It is also demonstrated that the fiber shows a high birefringence of 0.0221 at the wavelength 1550 nm. An elliptical air hole is introduced as a defect in the core region and this gives an additional flexibility to tailor the dispersion property. The proposed fiber can be used as an excellent candidate in wavelength-division-multiplexing optical fiber transmission system for residual chromatic dispersion compensation and also for maintaining single polarization.