We used multimode scanning acoustic force microscopy (SAFM) for studying no
ncollinearly propagating Rayleigh and Love wave fields. By analyzing torsio
n and bending movement of SAFM cantilever, normal and in-plane wave oscilla
tion components are accessible. The SAFM principle is the down-conversion o
f surface oscillations into cantilever vibrations caused by the nonlinearit
y of the tip-sample interaction. Through mixing of complementary oscillatio
n components, phase velocities of crossed Rayleigh waves on GaAs and crosse
d Rayleigh and Love waves on the layered system SiO2/ST-cut quartz were obt
ained simultaneously. Now, it is possible to investigate elastic properties
of submicron areas through multimode SAFM measurements. Finally, we presen
t mixing experiments of four SAWs on GaAs and discuss the various influence
s on the measured SAFM amplitude and phase contrast.