Fig. 1 A photonic crystal fiber with 7 periods in the cladding and with Λ ≈ 2.5μm and d ≈ 0.5μm.

Fig. 2. Measured dispersion for a selection of 7-period PCFs. Although the theoretical ideal fiber parameters were almost reached, the experimental and theoretical results did not match.

Fig. 3. Ultra-flattened dispersion photonic crystal fiber with 11 periods. Λ = 2.47μm and an average d of 0.57μm.

Fig. 4. Measured dispersion plots for ultra flattened dispersion PCF similar to the fiber shown in figure 3. Red curve: d = 0.58, Λ = 2.59, dark blue curve: d= 0.57, Λ=2.47.

Fig. 5. (a) shows the value of dispersion for variation of hole radius and pitch for a wavelength of 1500 nm. The black line represents zero dispersion. For the same fiber parameters (b) shows the value of the dispersion slope for a wavelength of 1500 nm. The black line represents zero slope. In both graphs the “×” shows the fiber parameters of the PCF with Λ = 2.47 μm and an average d of 0.57 μm and the “+” shows the PCF with Λ = 2.59 μm and an average d of 0.58 μm.