Efficient generation of 3.5Â W laser light at 515Â nm by frequency doubling a single-frequency high power DBR tapered diode laser

More than 3.5 W of green light at 515 nm is generated by frequency doubling a single-frequency high power DBR tapered diode laser. The frequency doubling is performed in a cascade of PPMgLN and PPMgSLT crystals in order to reach high power and avoid thermal effects present in PPMgLN at high power. The green light is diffraction limited (M2 <1.1) and single-frequency operation is demonstrated with a linewidth less than 2 pm.