Orthogonally Polarized Dual-Wavelength Pr:LLF Green Laser at 546 nm and 550 nm with the Balanced Output Powers at All Pump Power Level

A continuous-wave (CW) orthogonally polarized dual-wavelength (OPDW) Pr3+:LiLuF4 (Pr:LLF) green laser with a balanced output power on the 3P0→3H5 transition was demonstrated for the first time. We theoretically analyzed the conditions for achieving equal output power in the OPDW laser operation using two intracavity etalons and experimentally realized the OPDW green laser in a Pr:LLF crystal. Under pumping with a frequency-doubled optically pumped semiconductor laser (2ω-OPSL) generating 10 W at 479 nm, an OPDW green laser at 546 nm in π-polarization and 550 nm in σ-polarization was obtained with a total output power of 1.68 W. The output powers of the two wavelengths were equal for all the pump power levels. Further, a CW ultraviolet (UV) laser at 274 nm by intracavity sum-frequency mixing was also achieved with a maximum output power of 386 mW. The OPDW Pr:LLF green lasers with the balanced output power were desirable for medical detection and the generation of UV lasers.