Dynamic force microscopy at high cantilever resonance frequencies using heterodyne optical beam deflection method

We have developed a dynamic force microscope (DFM) with a wideband cantilever deflection sensor using heterodyne optical beam deflection (HOBD) method. The bandwidth of HOBD method is limited only by the maximum frequency for laser power modulation, which can be as high as gigahertz order. This technique allows us to use high cantilever resonance frequencies for improving the sensitivity and time response of DFM. In this letter, basic principle and experimental setup of HOBD method are described. Deflection measurement of a cantilever vibration at about 7 MHz is demonstrated. Using this cantilever, DFM imaging with a relatively fast scanning speed is performed. (C) 2004 American Institute of Physics.