Dual wavelength solid state laser

Abstract

A dual wavelength continuous wave (cw) solid state microlaser device that provides simultaneous laser action at a first and a second wavelength. The laser comprises a solid state gain material including a rare earth element having a first gain transition at the first wavelength and a second gain transition at the second wavelength. The gain material defines a block having a first face and a second, opposite face. A first reflective surface that is substantially reflective at both the first and second wavelengths is closely coupled to the first face. An output coupler provides a second reflective surface that is partially reflective at both the first and the second wavelengths, which is oriented with respect to the first reflective face to define an optical cavity through the first and second faces of the solid state gain material. An optical pump source is provided to end pump the solid state gain material with continuous pump radiation at a pump wavelength that is highly absorptive by the gain material. In some embodiments, the first reflective surface may be formed directly on the first face of the solid state gain material, and the second reflective surface may be formed directly on the second face of the solid state gain material. The resultant laser beam comprises two wavelengths each of which is believed to have a single longitudinal mode. In some embodiments the solid state gain material comprises a uniaxial crystal oriented within the optical cavity to provide polarized emissions for the first and second wavelengths.