Third harmonic frequency generation by type-I critically phase-matched LiB3O5 crystal by means of optically active quartz crystal.

We present a method of third harmonic generation at 355 nm by frequency mixing of fundamental and second harmonic radiation of an ytterbium nanosecond pulsed all-fiber laser in a type-I phase-matched LiB(3)O(5) (LBO) crystal where originally orthogonal polarization planes of the fundamental and second harmonic beams are aligned by an optically active quartz crystal. 8 W of ultraviolet light at 355 nm were achieved with 40% conversion efficiency from 1064 nm radiation. The conversion efficiency obtained in a type-I phase-matched LBO THG crystal was 1.

Highly efficient, narrow-linewidth, and single-frequency actively and passively Q-switched fiber-bulk hybrid Er:YAG lasers operating at 1645 nm.

High power, highly efficient single frequency oscillation of Er:YAG fiber-bulk hybrid laser at 1645 nm is demonstrated in actively and passively Q-switched operation modes. The slope efficiencies in the active and passive Q-switched operation reached 75% and 20%, respectively, with the record output powers in the narrow-linewidth and single longitudinal mode regimes of operation.

Pulsed and cw laser oscillations in LiF:F-2 color center crystal under laser diode pumping.

Continuous-wave laser oscillations in LiF:F-2 crystal optically pumped by a laser diode at 970 nm were demonstrated for what is believed to be the first time. The slope efficiency of 14% and conversion efficiency of 5.5% were achieved for 80 micros pump pulse duration and 5 Hz pulse repetition rate.