VIS, UV, and DUV wavelength extension of Yb:YAG diode-pumped thin-disk laser

A high-power picosecond laser offered to users at the HiLASE Laser Centre has been equipped with a harmonics generation system to expand application possibilities. The fundamental beam of 1030 nm is produced by a diode-pumped Yb:YAG thin-disk laser at ~1 ps pulse duration and 90 kHz repetition rate. Harmonic frequencies are produced from the fundamental wavelength; second (515 nm), third (343 nm), fourth (258 nm), and fifth (206 nm). The advantage of picosecond pulses when used for materials processing is a small thermal load on the sample surface. UV and DUV processing bring another advantage during the machining: micro-holes production with sharp cutting edges. The visible (VIS, 515 nm) and deep-ultraviolet (DUV, 258 nm) radiation are produced by frequency doubling of the fundamental and visible beams, respectively. The nonlinear crystals used for this are LBO (SHG) and CLBO (FHG). By sumfrequency mixing are generated the ultraviolet (UV) (1ω + 2ω = 3ω, 343 nm) and the deep-ultraviolet (DUV, 1ω + 4ω = 5ω, 206 nm). The crystals used are LBO (Type I, 3ω) and CLBO (Type I, 5ω). We present the latest results achieved at each harmonic, their optical properties and their typical applications. Recently, the laser provided the users with 75 W at the fundamental, up to 39 W at 515 nm, 21 W at 343 nm, 8 W at 258 nm and 1.5 W at 206 nm.