Gigahertz laser resonant ultrasound spectroscopy for the evaluation of transverse elastic properties of micrometric bers

The cross section eigenmodes of micrometric cylinders were measured in the range of several tenth of MHz to about 0:5 GHz. The vibrations were excited using subnanosecond laser pulses. The cross section eigenmodes were simulated using nite element modeling in a 2D geometry. Using the method of resonant ultrasound spectroscopy, the vibration spectrum of an aluminum wire of diameter 33 μm served to determine the transverse Young modulus and Poisson ratio with a precision of 0.7% and 0.3%, respectively. The calculated and measured frequencies of cross section eigenmodes were tted with a precision better than 0.5% in the 50-500MHz range