基于超连续谱的可调谐同步脉冲产生及噪声分析

A tunable dual-color synchronized picosecond pulse generation technique based on supercontinuum filtering is experimentally studied. The output pulse of an all-polarization-maintaining Er-doped fiber laser is divided into two channels, one of which is coupled to the highly nonlinear fiber, and the supercontinuum covering the emission band of Yb-doped fiber is obtained. With the combination of a narrow-band tunable filter with an all-polarization-maintaining Yb-doped amplifier, a tunable laser output with average power of 70 mW, pulse duration of 4.0 ps, and central wavelength of 10251055 nm is achieved. The other output of the Er-doped fiber laser passes through the narrow-band filter and the Er-doped fiber amplifier to generate a laser output with average power of 200 mW, pulse duration of 4.2 ps, and central wavelength of 1580 nm. The above tunable two-color picosecond pulse based on supercontinuum filtering possesses good synchronization characteristics and can be used as pump light and Stokes light for coherent anti-Stokes Raman scattering. It is found that the fluctuations of pulse amplitude and average power are smaller and the relative intensity noise is lower when the spectral components at flat positions of supercontinuum are selected as the seed light of the Yb-doped amplifier.