A Dual-Wavelength Cladding-Pumped Er³⁺/Yb³⁺ Codoped Fibre Laser System with More Than 2W Output and Tunable Wavelength Spacing

A dual-wavelength laser system with wideband tunable wavelength spacing and more than 2W output power is proposed and demonstrated. The operation principle of the laser system is based on the saturation gain characteristic of a cladding-pumped Er³⁺/Yb³⁺ co-doped fibre amplifier combining with a wideband tunable fibre laser with flat power spectrum. The tuning range of the wavelength spacing is continuous within a 35nm spectral range, and the power difference between both lasing wavelengths can be easily adjusted and controlled by a variable optical attenuator. The total output power can approximately keep unchangeable when the wavelength spacing and the power difference between both lasing wavelengths are continuously tuned and changed. The maximum total output power of the laser system is about 2.22W.