A novel pump scheme-chamfered-edge-pumping was employed for pumping a planar waveguide laser: A 12 mm-long edge was chamfered as a 0.2 mm wide bevel, pump light from the fast-axis-collimated LD was focused and coupled into the crystal through the chamfered-edge with a pump efficiency of 82%. The single-clad YAG/Nd:YAG/YAG planar waveguide was fabricated by thermal bonding technology with the geometry of 12 mm×5 mm×1 mm, which Nd:YAG core was 0.2 mm thick and symmetry claddings were 0.4 mm thick. A maximum output power of 15.5 W at 1064 nm with a slop efficiency of 37%, an optical-optical conversion efficiency of 31% and a M 2 value of 1.6 in the guided direction was achieved for a pump power of 50 W. The laser system realized a relatively high optical-optical conversion efficiency and excellent beam quality in guided direction.

In this letter, we demonstrate a novel 355 nm ultraviolet (UV) laser operating at ultrahigh repetition rate from 300 kHz to 1 MHz. The hybrid fiber-MOPA-bulk amplifiers based IR source exhibits a high average power of 105 W with near-diffraction-limited beam quality, narrow linewidth and high polarization extinction ratio. Two-cascaded LBO crystals are employed for high efficiency frequency tripling, and a maximum 43.7 W of average UV power is achieved at 400 kHz, corresponding to a conversion efficiency as high as 41.6%. The pulse duration of the UV pulse can be tuned from 5 to 10 ns with good pulse peak stability (better than 2.2% (RMS)).