The azimuthal dependence of third-order and cascaded second-order nonlinear coupling are used to measure the relative contributions of each to direct third-harmonic generation in β-barium borate. This enabled the measurement of the values of χ<sub>10</sub><sup>(3)</sup>, χ<sub>11</sub><sup>(3)</sup>, and χ<sub>16</sub><sup>(3)</sup> relative to the known χ<sub>ij</sub><sup>(2)</sup>. Finally, conversion efficiencies to 3ω of up to 6% from a single crystal were achieved with a femtosecond chirped-pulse-amplification laser with 200 GW/cm<sup>2</sup> in collimated beams.
© 2002 Optical Society of America
(190.0190) Nonlinear optics : Nonlinear optics
(190.2620) Nonlinear optics : Harmonic generation and mixing
(190.4400) Nonlinear optics : Nonlinear optics, materials
(190.7110) Nonlinear optics : Ultrafast nonlinear optics
(190.7220) Nonlinear optics : Upconversion
Paul S. Banks, Michael D. Feit, and Michael D. Perry, "High-intensity third-harmonic generation," J. Opt. Soc. Am. B 19, 102-118 (2002)