Thermophysical property measurements using time-resolved photothermal deflection spectrometry with step optical excitation

Abstract

This letter reports the theoretical and experimental results of thermophysical property measurements using our recently developed time-resolved photothermal deflection spectrometry (PDS) with step optical excitation. One-dimensional heat conduction boundary conditions of the third kind were derived, and a theoretical model with the boundary conditions was proposed. Both thermal diffusivity and effusivity of two well-known samples were precisely measured simultaneously by fitting experimental data to the theory. Thermal conductivity and unit volume specific heat then can be deduced. Moreover, time-resolved PDS with step optical excitation has the advantages of simpler experimental apparatus and less time consuming measurement, compared with the traditional periodically modulated PDS.