A novel technique for characterization of the second-order nonlinearity in nonlinear crystals is presented. It utilizes group-velocity walk-off between femtosecond pulses in type II SHG to achieve three-dimensional resolution of the nonlinearity. The longitudinal and transversal spatial resolution can be set independently. The technique is especially useful for characterizing quasi-phase-matched nonlinear crystals, and it is demonstrated in potassium titanyl phosphate.
© 2003 Optical Society of America
Stefan J. Holmgren, Valdas Pasiskevicius, Shunhua Wang, and Fredrik Laurell, "Three-dimensional characterization of the effective second-order nonlinearity in periodically poled crystals," Opt. Lett. 28, 1555-1557 (2003)