Fig. 1. (a) ZnSe waveguide structure, (b) refractive index of the core layer ZnSe, the cladding layer Ga₂As₃₀S₆₈ and Ge₅As₁₀S₈₅.

Fig. 2. Calculated dispersion curves of the fundamental quasi-TE (a) the dispersion parameter curves for the fundamental quasi-TE mode calculated from neff for eight waveguide geometries employing Ga₂As₃₀S₆₈ glass for both the upper and lower claddings, (b) and (c) Map of the dispersion parameter of w=4 and 8 μm ZnSe rib waveguides as a function of core thickness and wavelength, respectively, employing Ge₅As₁₀S₈₅ glass for both the upper and lower claddings. The dash lines show the change of the ZDWs

Fig. 3. The optical filed distribution for quasi-TE polarization in the waveguide （a-c） for w=4 μm， and （d-f） for w=8 μm waveguide with H1=2 μm andH2=1 μm at a wavelength of 2， 6， and 10 μm， respectively

Fig. 4. Effective area and nonlinear coefficient of the fundamental mode calculated in the waveguides (a) w = 4 μm, H1=2 μm, andH2=1 μm (b) w = 8μm, H1=2 μm, andH2=1 μm. (c) Dispersion distribution of the waveguides with w = 4 and 8μm. (d) The second-order dispersion of the waveguides with w = 4 and 8 μm.

Fig. 5. Simulated SC spectra at a pump wavelength of (a) 3.0 µm, (b) 4.5 µm, (c) 3.0 µm and (d) 4.5 µm for the two waveguides at different peak power up to 20 kW, respectively.

Fig. 6. Simulated SC spectra at different pump wavelengths of （a） 3.0 µm， （b） 3.5 µm， （c） 4.0 µm， and （d） 4.5 µm for the two waveguides with a peak power of 20 kW， respectively.

Fig. 7. The spectral evolution plots and temporal density plots corresponding to two curves in Fig. 5.2 (d) at a peak power of 20 kW for (a) the spectral evolution plot of 4 μm waveguide, (b) the spectral evolution plot of 8 μm waveguide, (c) the temporal density plot of 4 μm waveguide, (d) the temporal density plot of 8 μm waveguide.

Table 1. Refractive coefficient of ZnSe, Ga₂As₃₀S₆₈, and Ge₅As₁₀S₈₅.