Abstract
The photothermal method has been used for the determination of several thermal and optical material properties. We demonstrate the use of the photothermal method for the investigation of thermal and optical properties of the GaAlAsSb and GaInAsSb layers which are, respectively, the confinement layer and the active layer of the GaAlAsSb/GaInAsSb/GaAlAsSb/GaSb laser heterostructure. These layers were deposited on a GaSb substrate in its liquid phase by means of epitaxy.