Width-tunable optical RZ pulse train generation based on four-wave mixing in highly nonlinear fiber

We demonstrate a simple technique for width-tunable optical return-to-zero pulse train generation based on four-wave mixing in highly nonlinear fiber. By electrically tuning the delay between two pump pulse trains, the pulsewidth of a generated pulse train is continuously tuned. In our experiment, the full-width at half-maximum (FWHM) of a 5G pulse train is tuned from 85 to 25 ps, and the FWHM of a 10G pulse train is tuned from 33 to 18 ps. And the simulation results show that the FWHM of a 40G pulse train can be tuned continuously from 10.6 to 2.9 ps. Negligible power penalty is observed after 59-km single-mode fiber and 11.4-km dispersion-compensation-fiber transmission for different pulsewidths at 10 Gb/s.