Spectral interferometry with a supercontinuum is used for the first experimental measurement, to our knowledge, of phase dispersion of the fundamental mode in multiple bandgaps of a photonic bandgap fiber. The dispersion data show a strong influence of the Bragg scattering from the crystal structure surrounding the core. A simple two-dimensional model that includes the effects of a wavelength-dependent angle of propagation, where the angle is determined by the Bragg-scattering condition, and the effects of thin-film-like resonant scattering planes in the fiber is found to explain the observations qualitatively.
© 2003 Optical Society of America
J. Jasapara, Tsing Hua Her, R. Bise, R. Windeler, and D. J. DiGiovanni, "Group-velocity dispersion measurements in a photonic bandgap fiber," J. Opt. Soc. Am. B 20, 1611-1615 (2003)