Mode hop free tunable blue laser

A mode hop free tunable blue laser at 465 nm based on an external cavity system is investigated. The single longitudinal mode second-harmonic generation (SHG) blue laser was generated using quasi-phase matching (QPM) based MgO: PPLN pumped by infrared diode laser at 930 nm with one lasing longitudinal mode. The wide turning rang in excess of 100 GHz is achieved by using combination the etalon, silica glass plate and narrow band filter into the external cavity, which only allow one longitudinal mode running and operating wavelength tuning. 30 mw blue light was obtained at wavelength of 465 nm with beam quality better then M2 =1.3.