There are presented the results reached in the development of photoacoustic and photothermic techniques to study and analyze solids, liquids and gases. These are based on the conversion of luminous energy in heat, to a relatively low cost.

This scientific result embraces the development of these techniques in Cuba and their application in studies of interest for their implications in practice. The result's originality is backed by a patent. The authors have potentiated the use of these techniques starting from the development of theoretical models that have allowed applications in several fields related to physics, chemistry, environmental sciences and biology. These are propositions of experimental methods:

• To characterize physical transport and recombination parameters in surfaces and interfaces of semiconductor heterostructures,
• To detect pollutants to a level of traces in water and atmospheric air,
• To monitor fruit maduration from the detection of carbon dioxide and ethylene emitted.

These are up-to-date, deep and thorough works endorsed by:

• - 16 articles published in highly recognized Physics' magazines.
• - 12 publications in memoirs (proceedings) of international congresses
• - 2 doctorate and 1 master's degree theses defended

It is outstanding the fact that the work has been carried out in five years.