Equivalence between in-phase and antiresonant reflection conditions in Bragg fiber and its application to antiresonant reflecting optical waveguide-type fibers

It is shown by the phase calculation that equivalence in guiding principle holds between the in-phase and anti-resonant reflection conditions in the one-dimensional and cylindrically symmetric two-dimensional structures with periodic cladding. The in-phase condition is equivalent to a generalized quarter-wave stack (QWS) condition in the Bragg fiber. The generalized QWS condition is formally equivalent to the central gap point in the stratified planar antiresonant reflecting optical waveguide (SPARROW) model. The eigenvalue equations under the generalized QWS condition are identical to those in the limit of an infinite V parameter in the ARROW model. It was confirmed that the confinement loss shows its minima for the generalized QWS condition of the Bragg fiber. The phase calculation is applied to semiquantitatively understand the dependence of confinement and bend losses of the order of photonic bandgap in Bragg and ARROW-type fibers. (C) 2010 Optical Society of America