Noncollinear frequency conversion in the PPKTP

Summary form only given. Noncollinear interaction in birefringence phase-matched nonlinear crystals is usually used for the tuning of the output wavelength and group-velocity matching in short pulse optical parametric generators. The output beam shaping in travelling wave optical parametric generator (TOPG) with bulk crystal pumped by a Bessel beam in multiple noncollinear phase matching geometry has been demonstrated. In periodically poled KTiOPO/sub 4/ (KTP) (PPKTP) the effective nonlinear coefficients are several times larger than in the case of birefringence phase-matching. So relatively low parametric generation threshold has been demonstrated recently. We have investigated the second harmonic (SH) generation in PPKTP crystal pumped by Bessel beam in multiple noncollinear phase matching geometry.