Electro-acoustic analogies between thermoelastic component of the photoacoustic signal and low-pass RC filter

This paper presents a new approach to the thermal characterization of aluminum, based on the electro-acoustic analogy between the thermoelastic component of the photoacoustic signal and the passive RC low-pass filter. The analogies were used to calculate the characteristic thermoelastic cut-off frequencies of the photoacoustic component and obtain their relationship with the thickness of the aluminum samples. Detailed numerical analysis showed that the required relationship is linear in the loglog scale and can serve as a reference curve for the given material. The results of the numerical analysis were also confirmed experimentally.