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

We demonstrated a 36.9 W green laser with an intra-cavity second harmonic generation. A compact unstable V type cavity was adopted to compress the whole cavity configuration. The type I phase-matching LiB₃O₅ 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.