Photothermal measuring techniques using pulsed laser

An experimental set-up using different pulsed photothermal measuring techniques is presented. The set-up allows investigation of different optical components byu means of the photothermal reflectance microscopy, photothermal transmittance microscopy and the photothermal deflection microscopy both in reflection and transmission. The methods are based on different effects, such as a surface bending caused by thermally induced stress and thermal stress dependence of the refractive index. Therefore and in consequence of different reflectance's of the components, each photothermal techniques has different measuring sensitivity. The combination of several photothermal techniques allows an investigation of all optical component classes. Otherwise, more information could be determined about optical, thermal and mechanical properties of components. The experimental results of various optical components are presented. The absorbance, reflectance, transmittance and thermally conductivity are discussed on the basis of temporally measured signal curves. Thermally induced stress was also detected by means of the photothermal deflection microscopy in transmission.