Small signal amplification using parametric resonance in NcAFM imaging

The power-spectral analysis of the cantilever signal in large amplitude non-contact atomic force microscopy (NcAFM) is carried out with a view to understanding the dynamics of the system. The analysis shows period doubling bifurcation with respect to mean tip–sample separation. It is observed that period doubling bifurcation can be used for mechanical amplification of small signal using parameter modulation. The possibility of using parametric amplification for the imaging of periodic lattice is proposed. An attempt has been made to image freshly cleaved NaCl single crystal and as received Si(1 1 1) surfaces in ambient conditions.