Dynamic visualization of subangstrom high-frequency surface vibrations
08 January 2001
An optical scanning interferometer for accurate imaging of high-frequency surface vibrations is described. Vertical-displacement (out-of-plane) resolution of the interferometer is similar to0.003 Angstrom, while lateral resolution is diffraction limited, typically similar to0.5 mum. The high-frequency response is limited by the detector to similar to6 GHz. Both the magnitude and phase are recorded at each point of the scan, so that an accurate measurement of the instantaneous surface shape is obtained. Furthermore, the phase information allows one to make a slow-motion movie of the vibrating surface. Data are presented for three examples in the frequency range 4 MHz-2 GHz. (C) 2001 American Institute of Physics.