Generation of femtosecond laser pulses at 263 nm by K_3B_6O_(10)Cl crystal

The third harmonic generation(THG) of a linear cavity Ti:sapphire regenerative amplifier by use of a K_3B_6O_(10)Cl(KBOC) crystal is studied for the first time. Output power up to 5.9 mW is obtained at a central wavelength of 263 nm,corresponding to a conversion efficiency of 4.5% to the second harmonic power. Our results show a tremendous potential for nonlinear frequency conversion into the deep ultraviolet range with the new crystal and the output laser power can be further improved.     

Generation of femtosecond laser pulses at 396 nm in K_3B_6O_(10)Cl crystal

K_3B_6O_(10)Cl(KBOC), a new nonlinear optical crystal, shows potential advantages for the generation of deep ultraviolet(UV) light compared with other borate crystals. In this paper we study for the first time the second harmonic generation(SHG) of a femtosecond Ti:sapphire amplifier with this crystal. Laser power is obtained to be as high as 220 m W at the central wavelength of 396 nm with a 1-mm-long crystal, and the maximum SHG conversion efficiency reaches 39.3%. The typical pulse duration is 83 fs. The results show that second harmonic(SH) conversion efficiency has the room to be further improved and that the new nonlinear crystal is very suited to generate the high efficiency deep ultraviolet laser radiation below 266 nm.