Spatial-temporally resolved high-frequency surface acoustic waves on silicon investigated by femtosecond spectroscopy

MARTIN SCHUBERT; MARTIN GROSSMANN; OLIVER RISTOW; MIKE HETTICH; AXEL BRUCHHAUSEN; ELAINE C. S. BARRETTO; ELKE SCHEER; VITALYI GUSEV; THOMAS DEKORSY

APPLIED PHYSICS LETTERS

AMER INST PHYSICS

Lugar: American Institute of Physics; Año: 2012 vol. 110 p. 13108 - 13108

0003-6951

Various types of surface acoustic waves are generated by femtosecond pulses on bulk silicon with aluminium stripe transducers. Rayleigh and leaky longitudinal surface acoustic wave modes are detected in the time domain for various propagation distances. The modes are identified by measuring on various pitches and comparing the spectra with finite element calculations. The lifetimes of the modes are determined quantitatively by spatially separating pump and probe beam, showing a significant difference in the lifetimes of both modes. We were able to excite and measure Rayleigh modes with frequencies of up to 90 GHz using a 100 nm period grating.