Bending of Semiconducting Cantilevers Under Photothermal Excitation

In this study, the elastic vibrations of semiconducting cantilevers, which were excited with a frequency-modulated uniform laser beam, were studied theoretically and experimentally. The three-dimensional distributions for the carrier density and temperature were obtained analytically using the Green function method. The elastic bending of a cantilever was given by the theory of a thin rectangular plate. Using an optical interferometric setup, the experimental photothermal signals were investigated near the first resonant frequency and the results showed that the theoretical calculation results were in good agreement with that of the experimental measurement.