title: Backward second-harmonic and third-harmonic generation in a periodically poled potassium titanyl phosphate waveguide.
abstract: We observed backward second-harmonic and backward third-harmonic generation in a periodically poled KTiOPO(4) waveguide using nanosecond laser pulses. The highest conversion efficiency achieved for the backward second-harmonic generation, occurring at the 25th-order grating, was ~0.6% . The backward third-harmonic generation was the result of mixing the pump beam with the forward or the backward second-harmonic beam. Conversion efficiency of ~0.4% was achieved at a pump wavelength of 1233.7 nm, where the two constituent nonlinear processes are both quasi-phase matched.
authors: X
authors: X
authors: Gu
authors: M
authors: M
authors: Makarov
authors: Y J
authors: YJ
authors: Ding
authors: J B
authors: JB
authors: Khurgin
authors: W P
authors: WP
authors: Risk