Orthogonally polarized dual-wavelength Pr:LiGdF4 lasers in the green range

We demonstrate a diode-pumped continuous-wave tunable orthogonally polarized dual-wavelength Pr:LiGdF4 laser in the green range. The excellent mode matching between the pump and green lasers is achieved under the consideration of thermally induced effects. We analyze the condition of gain-to-loss balance via an uncoated glass etalon to achieve the dual-wavelength operation. At an absorbed pump power of 17.9 W, a dual-wavelength laser operating at 546 nm in π-polarization and 538 nm in σ-polarization with 1.72 W of average output power was obtained. Orthogonally polarized dual-wavelength laser operation at shorter- or longer-wavelength pairs with lower average output power could also be realized for other output-coupling transmissions. To the best of our knowledge, this is the first work realizing orthogonally polarized dual-wavelength operation in Pr:LiGdF4 lasers.