Switchable lasing of 1040 and 1537-nm lines based on the optical bistability in the pump-bypassed ytterbium-doped fiber laser

摘要

Lots of attention has been paid to the optical bistability in fiber optical because its potential application in optical information processing and fiber optical communication. Recently the optical bistability in erbium-doped active fiber induced by the nonlinear absorption of the fiber has been investigated. In this paper, we demonstrated the strong optical bistability in the ytterbium-doped fiber laser with the pump-bypassed cavity configuration. In this original configuration, the fiber laser is divided into the gain stage and absorption stage by a WDM. As the function of incident pump power, both the 976nm residual pump intensity and the 1040nm laser signal of this laser exhibit ～320mW-wide optical bistabilities in an antiphase manner with respect to each other. Further the residual pump power is directed to pump the second Er and Yb co-doped fiber laser cavity to generate the lasing at 1537nm. As a result of the optical bistability in the residual pump, the lasings of 1040nm and 1537nm are switchable between each other. Worthwhile to point out, these two wavelengths are located in the two wavelength windows applicable for the free-space laser communications, respectively. Therefore the switchable 1040 and 1537nm source by combining the bistable feature of Yb fiber laser with the hybrid cavity configuration (pump-bypassed cavity plus the bifurcated cavity could have important application at this aspect.