The invention pertains to an apparatus and method for controlled laser heating of a body. An optical integrating chamber, with an opening adjacent to the surface of the body, has a first and second aperture. A laser source, produces a beam of known power which is directed through the first aperture and the chamber opening onto the surface. A portion of the power of the laser beam is absorbed by the body, thereby heating it locally, and the remaining portion is substantially reflected back into the chamber. A photodetector samples the reflected light accumulated within the chamber through the second aperture, thereby discerning the total power of the reflected light, and enabling the computation of the absorbed power imparted as heat to the body. This computation is performed by a computer or controller, which also serves as a control feedback mechanism, by which the application of the laser is controlled based on the absorbed power imparted to the body during the heating process. Several embodiments are described, useful for a wide range of potential applications in processing and evaluation of organic and inorganic materials and structures.
