Thermoelastic imaging using optical interferometer : sensitivity optimization and super-resolution

Abstract

The noncontacting thermoelastic microscope is based on ~r + laser excitation and optical probe detection. The main problem is to adjust the experimental parameters for sensitivity optimisation. This paper points out that 3-D model predicts the sample thermoelastic behaviour. Calculated criteria enable the choice of the best values of parameters. Experimental results show the advantage of an imaging criterion : particularly contrast of metallic sample images is related to the relative position of excitation and detection beams.

Measurement of cantilever vibrations with a new heterodyne laser probe: application to scanning microdeformation microscopy

“…The results show the effect of the tip-sample interaction on the resonant frequencies of the cantilever in SMM. The data obtained confirm that the proposed probe enables an accurate estimation of the local elastic constants of the sample.Heterodyne interferometry is a useful tool for probing small displacements generated with electrical (e.g., piezoelectric transducer), magnetic, or thermal sources [1][2][3][4][5][6][7][8]. The main advantages of optical probing are the absence of contact or mass loading, wide bandwidth (up to about 1 GHz, limited by the detection electronics and by the spot size), and local measurement.…”