Tunable Supercontinuum Generated in a Yb3+-Doped Microstructure Fiber Pumped by Ti:Sapphire Femtosecond Laser**Supported by the National Natural Science Foundation of China under Grant No 61735011, the Natural Science Foundation of Hebei Province under Grant Nos F2016203389 and F2018105036, the Science and Technology Research Project of College and University in Hebei Province under Grant No BJ2017108, the Open Subject of Jiangsu

Abstract

We experimentally demonstrate that a tunable supercontinuum (SC) can be generated in a Yb3+-doped microstructure fiber by the concept of wavelength conversion with a Ti:sapphire femtosecond (fs) laser as the pump. Experimental results show that an emission light around 1040nm in an anomalous dispersion region is first generated and amplified by fs pulses in the normal dispersion region. Then, SC spectra from 1100 to 1380nm and 630 to 840nm can be achieved by combined effects of higher-order soliton fission and Raman soliton self-frequency shift in the anomalous dispersion region and self-phase modulation, dispersive wave, and four-wave mixing in the normal dispersion region. It is also demonstrated that the 20nm change of pump results in a 280nm broadband shift of soliton and the further red-shift of soliton is limited by OH− absorption at 1380 nm.