Leaky-wave resonances in second-harmonic generation induced by surface transient grating

Summary form only given. In this work, it is shown that leaky-wave resonances in the second-harmonic generation can be observed not only on the "permanent" diffraction gratings, but also on the two-wave induced surface transient gratings. An enhancement and bistability of the second-harmonic generation appears at these leaky-wave resonances on the induced surface transient grating defined basically by surface contribution caused by the surface enhanced local field due to excitation of surface polaritons. It can be important for nonlinear optical probing of surfaces and thin films due to higher sensitivity stipulated by enhanced second-harmonic signal.