Photothermal Measurement by the Use of Scanning Thermal Microscopy

The possibility of using the photothermal effect for generation of a temperature disturbance in quantitative thermal measurements based on utilization of a scanning thermal microscope is analyzed. It was assumed that the periodical temperature disturbance caused by absorption of intensity-modulated light can be probed by the temperature sensor of the scanning thermal microscope operating in a passive mode. To analyze the temperature field in a sample illuminated by a focused obliquely incident light beam, a numerical model of the experiment was developed using the finite element method. Numerical simulation showed that the considered measuring method potentially can provide information about the thermal properties of the sample; however, the spatial resolution of measurements will be relatively low. Experiments confirmed correctness of the developed model.