Soliton self-frequency shift simulation of cascades of fluorotellurite fiber and chalcogenide fiber

We numerically investigate a Raman soliton source cascaded by a fluorotellurite fiber and a chalcogenide fiber. By using a 2.8 μm fiber laser with a pulse width of 137 fs as the pump light, widely tunable Raman solitons spanning from 2.8 to 8.1μm are observed in the nonlinear media cascaded by 5 cm fluorotellurite fiber and 10 cm chalcogenide fiber. The pulse width of the red-shift soliton at 8.1 μm is 132 fs. For the first time we propose the idea of coupling the tellurite fiber and chalcogenide fiber to further enhance the SSFS effect in mid infrared region (MIR). Our simulated results show the possibility of generating long wavelength Raman soliton use a source cascaded by fluorotellurite fiber and chalcogenide fiber