Dispersion properties of hollow-core photonic bandgap fibers based on a square lattice cladding

• Published in: Optics communications 2008-07, Vol.281 (13), p.3486-3491
• Main Authors: Zhang, Hu, Wang, Qiuguo, Yang, Bojun, Yu, Li
• Format: Article
• Language: English
• Subjects: Applied sciences; Circuit properties; Confinement loss; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Full-vector finite element method; Fundamental areas of phenomenology (including applications); Integrated optics. Optical fibers and wave guides; Optical and optoelectronic circuits; Optical elements, devices, and systems; Optical waveguides and coupleurs; Optics; Photonic bandgap fibers; Physics; Square lattice; Waveguide GVD
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2008.03.005

In this paper the dispersion properties and confinement loss of hollow-core photonic bandgap fibers (PBGFs) based on a square lattice (SL) with rounded square air-holes was investigated for the first time, by using a full-vector finite element method (FEM). The waveguide group velocity dispersion (GVD) curves with different core diameter D, air hole size d, rounded diameter d c and hole pitch Λ are presented. The influence of the number of cladding rings on dispersion and confinement loss were also calculated. It was found that as Λ or d increases, the width of PBG becomes wider, and that D and the number of cladding rings have a smaller influence on waveguide GVD. The ratio between bandgap width and central wavelength in our simulation is about 38.1%, which is larger than that of hollow-core PBGFs with triangular lattice (TL) (∼25%). By simulation, the desired zero dispersion wavelength or desired dispersion slope could be obtained by properly choosing the value of d c or Λ. Compared to TL PBGF, at least nine cladding rings is needed to achieve the confinement loss less than 0.1 dB/m for future application.