The use of low-index-contrast photonic bandgap (PBG) fiber for transmission of short pulsed light is discussed. PBG fibers have positive waveguide dispersion at long wavelengths at which conventional index-guiding fibers have negative waveguide dispersion. PBG fibers with low-index contrast can be used to obtain fibers with zero dispersion and a large mode area below 800 nm$+3$/. The results show that the PBG fiber is less sensitive to nonlinear effects and allows transmission of considerably larger intensities.
Riishede, J., Lægsgaard, J., Broeng, J., & Bjarklev, A. O. (2004). Low index-contrast photonic bandgap fiber for transmission of short pulsed light. Optics & Photonics News, 15(12), 26. https://doi.org/10.1364/OPN.15.12.000026