We present a passively mode-locked semiconductor disk laser (SDL) emitting at 650nm with intra-cavity second harmonic generation to the ultraviolet (UV) spectral range. Both the gain and the absorber structure contain InP quantum dots (QDs) as active material. In a v-shaped cavity using the semiconductor samples as end mirrors, a beta barium borate (BBO) crystal is placed in front of the semiconductor saturable absorber mirror (SESAM) for pulsed UV laser emission in one of the two outcoupled beams. Autocorrelation (AC) measurements at the fundamental wavelength reveal a FWHM pulse duration of 1.22ps. With a repetition frequency of 836MHz, the average output power is 10mW per beam for the red emission and 0.5mW at 325nm.
Publication: Intra-cavity frequency-doubled mode-locked semiconductor disk laser at 325 nm
Roman Bek, Stefan Baumgärtner, Fabian Sauter, Hermann Kahle, Thomas Schwarzbäck, Michael Jetter, and Peter Michler 
Opt. Express 23(15), 19947-19953 (2015)
Contact person: Dr. M. Jetter