Mid-infrared frequency conversion via normal dispersion modulation instability in chalcogenide fibers

摘要

Mid-infrared frequency conversion via normal dispersion modulation instability in chalcogenide fibers has been numerically investigated by calculating the phase matching conditions and solving the generalized nonlinear Schrodinger equation. The core material of the chalcogenide fibers is As_2Se_3 and the cladding material is As_2S_5. Usually, the larger converted wavelength spacing between the pump and the far-detuned converted signal, the smaller gain. Therefore, the dispersion of the chalcogenide fibers are optimized to balance the gain and the converted signal wavelength spacing. The results show that the converted far-detuned mid-infrared signal can be tuned to 10 μm. The results also show that for a pumping source with the fixed wavelength, the far-detuned frequency conversion can be optimized by controlling the core size of step-index chalcogenide fibers. By using the simple step-index structure and controlling the core size of the chalcogenide fibers, the far-detuned mid-infrared frequency conversion can be achieved.