Processing of thermal mirror signals under continuous wave excitation

The main features of the photothermal mirror signals arising under the continuous wave excitation were analyzed in terms of a model that takes account of thermal, mechanical, and diffraction effects. Formulae to describe the initial slope and stationary value of the signal were derived and compared with the numerical simulation results. We suggested an approach to processing the thermal mirror signals based on exploiting the initial slope and stationary value. The method was verified using numerical simulation and experimental results. We compared the method performance with the conventional approach using thermal mirror signals excited in the luminescent glasses. It was shown that the developed technique has an essentially lower computational cost, while offering a comparable level of accuracy.