Wavelength-tunable few-cycle optical pulse generation from an all-fiber erbium-doped laser system

In this work, to create widely wavelength-tunable few-cycle pulses, we propose to use the following three- stage scheme for nonlinear transformation of femtosecond pulses from the conventional modelocked erbium- doped setup. A silica fiber with slowly decreasing dispersion (DDF) is used for preliminary pulse compression and central wavelength tuning over a broad range at the first stage. At the second stage, the highly nonlinear dispersion-shifted fiber with a small normal dispersion is spliced to the DDF for supercontinuum generation, which is then compressed (third stage) to the few-cycle pulse in the fiber compressor.