Effects of dispersion on characterization of multi-wavelength Q-switched fiber laser

Abstract

In this paper, a real-time switchable and reconfigurable multi-wavelength Q-switched fiber laser has been experimentally carried out, which is based on a real-time configurable filter (WaveShaper) and a section of unpumped erbium–ytterbium co-doped fiber (EYDF) as a saturable absorber (SA). The proposed multi-wavelength Q-switched laser has been demonstrated to generate different combination of wavelengths at 100 GHz and 200 GHz International Telecommunications Union (ITU) grids specifications. The WaveShaper not only acts as a multi-channel filter but also introduces wavelength-dependent loss (WDL) in the laser cavity. The WDL can effectively suppress the mode competition caused by homogeneous gain broadening of EDF. The attenuation at each wavelength is adjusted to equalize optical power of different channels. The effects of dispersion on the performance of multi-wavelength Q-switched fiber laser are investigated by introducing additional dispersion from WaveShaper. No significant wavelength drift was observed after monitoring of an hour, multi-wavelength Q-switched operation is clearly demonstrated with a good stability at room temperature.