title: Single-mode regime of square-lattice photonic crystal fibers.
abstract: The modal cutoff of square-lattice photonic crystal fibers with a finite number of air-hole rings has been accurately investigated to our knowledge for the first time. By analyzing the leaky behavior of the second-order mode, we have obtained a phase diagram that describes the regions of single-mode and multimode operation as well as the endlessly single-mode regime. Furthermore, starting from these results, we have obtained the cutoff normalized frequency according to two different formulations of the V parameter previously adopted for fibers with a triangular lattice. A final comparison of the cutoff properties of fibers characterized by a square lattice and a triangular lattice has been carried out.
authors.affiliation: Information Engineering Department, University of Parma, Parco Area delle Scienze 181/A, 43100 Parma, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Poli
authors.forename: M
authors.initials: M
authors.lastname: Foroni
authors.forename: M
authors.initials: M
authors.lastname: Bottacini
authors.forename: M
authors.initials: M
authors.lastname: Fuochi
authors.forename: N
authors.initials: N
authors.lastname: Burani
authors.forename: L
authors.initials: L
authors.lastname: Rosa
authors.forename: A
authors.initials: A
authors.lastname: Cucinotta
authors.forename: S
authors.initials: S
authors.lastname: Selleri