Development and characterization of highly-nonlinear multicomponent glass photonic crystal fibers for mid-infrared applications

We present a detailed chromatic dispersion characterization of heavy-metal oxide (HMO) glass photonic crystal fibers (PCFs) suitable for mid-infrared applications. Based on previous work with hexagonal and suspended-core fibers the focus was placed on determination of the chromatic dispersion curve to reach precise correlation between simulation model and real fiber based on both a post-draw model correction and broadband chromatic dispersion measurement. The paper covers the fiber design, discusses fiber manufacturing, presents measurements of fiber chromatic dispersion, provides the simulation model correction and finally proposes further applications. Selected fiber designs from simulation model were fabricated by the stack-and-draw technique. The dispersion measurement setup was based on an unbalanced Mach-Zehnder interferometer. The influence of optical elements on the measurement results and broadband coupling is discussed. We have proved that the critical factor represents the accuracy of the refractive index equation of the HMO glass and real fiber structure. By improved technique we reached the zero-dispersion wavelength with a reasonable precision of less than 30 nm.