Fig. 1. (a) Dimensions and (b) dispersion profiles for the tapered triangular PCF with relative hole diameter d/Λ = 0.57 and pitch Λ = Λ₀ = 1.0 μm (untapered) to Λ = Λ_T = 0.9 μm, in steps of 0.01 μm. The dispersion is normal for all wavelengths for Λ < 0.96 μm. (c) Dispersion coefficients β ₂ [10^-27 s²/m] (red, 엯), β ₃ [10^-41 s³/m] (green, ◻), β ₄ [10^-55 s⁴/m] (black, ▵), and β ₅ [10^-70 s⁵/m] (blue, ◁), versus pitch Λ.

Fig. 2. Color coded power spectrum plot of the spectral evolution in a z _T = 15 mm long taper with final pitch (a) Λ_T = 0.98 μm and (b) Λ_T = 0.93 μm. The white line represents the ZDWs with the dispersion being anomalous inside this curve.

Fig. 3. (a, i) Power spectrum for an untapered PCF with Λ _T = 1.0 μm at z = 0 mm (dotted, red), 8 mm (dashed, green), and 15 mm (solid, blue). (b, i) Power spectrum at taper end z = z _T = 15 mm for Λ_T = 0.9 μm (dotted, red), 0.95 μm (dashed, green), and 1.0 μm (solid, blue). (c, i) Power spectrum for Λ_T = 0.9 μm at taper end z = z _T = 15 mm (dotted, red), 25 mm (dashed, green), and 50 mm (solid, blue). (d, i) Power spectrum at taper end z = z _T = 15 mm for Λ_T = 0.9 μm and average pump power 6 μW (dotted, red), 6 mW (dashed, green), and 12 mW (solid, blue). (a-d,ii) center wavelength, (a-d, iii) FWHM, and (a-d, iv) average power within the FWHM versus respective parameters, NIR (엯) and VIS spectral parts (◁).