Tunable Ultraviolet Second Harmonics Generation Pumped by Supercontinuum Laser

This paper presents the first systematic study on second harmonics generation based on a supercontinuum source. We analyzed the effect of the supercontinuum beam diameter and the crystal length to generate second harmonics. The walk-off effect on the second harmonics was also investigated; the efficiency was limited by the walk-off, and the beam of the second harmonic was out of shape. A tunable ultraviolet in the range of 285–340 nm is obtained with the pump of a visible supercontinuum, which is generated by a laser with an all-fiber device. The results provide a theoretical basis for the improvement of the second harmonic power and optimization of the crystal and beam diameters. A potentially tunable ultraviolet with a power exceeding 10 mW can be obtained by a high-power supercontinuum pump.