Compact high conversion efficiency Nd:YAG/LBO green laser using unstable V cavity

Abstract

We demonstrated a 36.9 W green laser with an intra cavity second harmonic generation. A com pact unstable V type cavity was adopted to compress the whole cavity configuration. The type I phase match ing LiB 3 O 5 was used as the nonlinear crystal in the second harmonic generation. The 36.9 W average power and 38 ns pulse width of 532 nm green laser was obtained at a repetition rate of 10.3 kHz, corresponding to a peak power of 94 kW. The optical to optical conversion efficiency from diode to green and from IR to green laser was about 19.8 and 82%, the whole cavity length is about 300 mm. To the best of our knowledge, this is the shortest cavity configuration of side pump green system with output power higher than 30 W and IR to green conversion efficiency larger than 80%. The output fluctuation of this system was less than 3% in 2 h.

Efficient high-pulse-energy eye-safe laser generated by an intracavity Nd:YLF/KTP optical parametric oscillator: role of thermally induced polarization switching

“…The birefringence-induced polarization switching may be the main mechanism why efficient intracavity nonlinear frequency conversions, such as harmonic generations [9][10][11][12] and optical parametric oscillations [13][14][15][16][17], can be successfully realized by using the optically isotropic materials without any active polarization control in the optical resonator. For example, the output power as high as 36.9 W at 532 nm with the Nd:YAG crystal has been achieved by using an intracavity frequency doubling configuration [12], and the intracavity Nd:YAG/KTA optical parametric oscillator (OPO) has efficiently generated the eye-safe radiation at 1.54 µm with the output power up to 12.7 W [17]. However, so far the effect of the birefringence-induced polarization switching in the process of intracavity nonlinear frequency conversion has not been experimentally manifested.…”