Alternate and simultaneous generation of 1-GHz dual-wavelength pulses from an electrically tunable harmonically mode-locked fiber laser

A new scheme of producing dual-wavelength mode-locked pulses from a fiber laser is proposed and experimentally demonstrated. In addition to the simultaneous generation of two selected wavelength components, the scheme also allows the alternate generation of mode-locked pulses at different wavelengths. The alternate switching of wavelengths is demonstrated at 1 GHz, and has been achieved over an electrical tuning range of 13.1 nm using the dispersion-tuning approach. A constant mode spacing of 7.1 nm is maintained during the tuning process.