Third-harmonic generation in barium borate.

The cubic nonlinear susceptibility of barium metaborate was employed for the generation of phase-matched third-harmonic generation (THG) of 1.053-microm pump radiation. The various processes that are responsible for THG in this crystal are discussed and experimental results for types I and II phase matching are presented. THG power of 50 microW is recorded with an average pump power of 800 mW of 1-kHz repetition rate picosecond pulses.