Generation of second harmonic light with a wavelength of 560Â nm in a compact module

We demonstrate a continuous wave 133 mW laser module at 560.5 nm on a 50 mm·10 mm optical bench. The setup consists of a 1121 nm distributed Bragg reflector ridge waveguide laser and a MgO:LiNbO3 quasi-phase matched ridge waveguide crystal, which are coupled by a grin lens, as well as two cylindrical lenses for beam collimation behind the crystal. A novel approach to ensure phase matching is used. The laser and the crystal are stabilized by the same heat sink and only the wavelength of the laser is tuned by heating the distributed Bragg reflector section of the laser. This reduces the influence of temperature variations on the module's performance enabling operation with output power variations <10% over a temperature range of 20 K. The size and robustness against temperature variations of this setup make it an interesting candidate for future biomedical applications.