Nanoscale surface displacement is used to determine thermo-optical–mechanical properties of high absorbing solids by means of the time-resolved thermal mirror method. The thermoelastic equation for the surface displacement and an expression for the probe beam intensity at the detector plane were derived. Experiments were performed in a high absorbing TiO2-doped low silica calcium aluminosilicate glass, and obtained the valuable values of the fluorescence quantum efficiency and thermal properties. The results indicate that this method is reliable for the characterization of semitransparent, high absorbing, and opaque materials.