Width and wavelength-tunable optical pulse train generation based on four-wave mixing in highly nonlinear photonic crystal fiber

We demonstrate both width and wavelength-tunable optical pulse train generation based on four-wave mixing in highly nonlinear photonic crystal fiber. By tuning the delay time between two pulse trains, the pulsewidth of the generated pulse train is continuously tuned. By tuning the wavelength of one of the pulse trains, the wavelength of the generated pulse train is also continuously tuned. In our experiment, the pulsewidth of a 5-GHz repetition rate pulse train is tuned from 88 to 19 ps and the pulsewidth of a 10-GHz pulse train is tuned from 39 to 19 ps. The 3-dB wavelength tuning range is about 70 nm.