title: Highly birefringent photonic crystal fiber with ultra-flattened negative dispersion over S  +  C  +  L  +  U bands.
abstract: We present a new cladding design for photonic crystal fiber (PCF) on a decagonal structure to simultaneously achieve ultra-flattened large negative dispersion and ultrahigh birefringence. Numerical results confirm that the proposed PCF exhibits ultra-flattened large negative dispersion over the S+C+L+U wavelength bands and average dispersion of about -558.96  ps/nm/km with absolute dispersion variation of 9.7  ps/nm/km from 1460 to 1675 nm (215 nm bandwidth). Moreover, ultrahigh birefringence of 0.0299 is also achieved at a 1500 nm wavelength.
authors.forename: Md
authors.initials: M
authors.lastname: Selim Habib
authors.forename: Emran
authors.initials: E
authors.lastname: Khandker