Tunable single-frequency Yb:YAG microchip green laser

Summary form only given. Yb:YAG is an attractive quasi-four level laser, because there is only one excited-state manifold. Thus there are no undesirable loss processes such as excited-state absorption, upconversion and concentration quenching. These characteristics bring about several advantages relative to Nd:YAG for diode laser pumping, which are a high quantum efficiency of over 90%, reduced heat generation in the laser material and a longer upper-state lifetime of nearly 1 ms. In addition, the wide emission bandwidth of the material around 1 /spl mu/m allows tunable and/or mode-locked operation. Specifically, a widely tunable green laser is achievable around the Ar-ion laser wavelength of 515 nm by frequency doubling. Therefore a frequency-doubled Yb:YAG laser is able to replace an Ar-ion laser and its applications. We report a widely tunable intracavity frequency-doubled Yb:YAG microchip laser in single-axial-mode oscillation.