In this paper, dispersion compensating photonic crystal fiber with triple-cladding is put forward and the property of high negative dispersion is investigated. Plane-wave expansion (PWE) method is used to analyze. We discuss the variation of the dispersion in detail, with changing the geometry parameters. A triple-cladding dispersion compensating photonic crystal fiber with dispersion -4140 ps/nm/km and FWHM 10 nm is demonstrated at 1550 nm wavelength.
A new dual-pump fiber optical parametric amplifier (FOPA) is investigated, which is composed of three-section photonic crystal fibers (PCF) and theoretically provides a nearly flat gain of 21.54 dB with peak-to-peak gain uniformity of better than 0.2-dB over the 405-nm bandwidth from 1260 nm to 1665 nm. Moreover, the influence of random fluctuations of the second-order dispersion in each fiber segment on the gain spectrum also is analyzed. When the average values of second-order dispersions are maintained close to the constant optimum values, the deviation of gain spectra is not large and the gain ripple is not more than 3 dB in presence of second-order dispersion variations.