660 nm and 974 nm Dual-Wavelength Pumped Er3+/Dy3+ Codoped ZBLAN Fiber Laser

In this work, we experimentally report a wavelength-tunable Er3+/Dy3+ codoped ZBLAN fiber laser via employing the strategy of 660 nm and 974 nm dual-wavelength pumping, for the first time, to our knowledge. Based on the combined effects of the F-4(9/2) -> I-4(9/2) and H-6(13/2) -> H-6(15/2) transitions from Er3+ and Dy3+ ions, respectively, the tunable spectral range of 2930 3681 nm (751 nm) was obtained, representing the broadest level of rare-earth-doped mid-infrared fiber lasers. More importantly, the gain distribution of the laser could be managed by controlling the ratio of the dual-wavelength pump powers, hence yielding an ultraflat subrange of 3.2 3.4 mu m, with a low power fluctuation of <3% around 700 mW. This dual-wavelength pumped architecture provides an optional mid-infrared photonics platform for designing broadband tunable oscillators and amplifiers.