@article{SkoczowskyJechowStuermeretal.2010, author = {Skoczowsky, Danilo and Jechow, Andreas and St{\"u}rmer, Herbert and Poßner, Torsten and Sacher, Joachim and Menzel, Ralf}, title = {Quasi-monolithic ring resonator for efficient frequency doubling of an external cavity diode laser}, issn = {0946-2171}, doi = {10.1007/s00340-009-3802-7}, year = {2010}, abstract = {A quasi-monolithic second-harmonic-generation ring resonator assembled with miniaturized components is presented. The ring contains a 10-mm-long bulk periodically poled lithium niobate crystal for second-harmonic generation, four plane mirrors and two gradient-index lenses. All parts are mounted on a glass substrate with an overall size of 19.5 mmx8.5 mmx4 mm. As pump source a broad-area laser diode operated in an external resonator with Littrow arrangement is utilized. This external cavity diode laser provides near diffraction limited, narrow-bandwidth emission with an optical output power of 450 mW at a wavelength of 976 nm. Locking of the diode laser emission to the resonance frequency of the ring cavity was achieved by an optical self-injection locking technique. With this setup more than 126 mW of diffraction-limited blue light at 488 nm could be generated. The opto-optical conversion efficiency was 28\% and a wall plug efficiency better than 5.5\% could be achieved.}, language = {en} }