Infrared laser holography used in fusion plasma studies

A method of producing holographic images using invisible infrared rays was proposed at the Georgian Academy of Sciences' Institute of Physics. It makes it possible not only to reproduce the object being depicted in three dimensions, but also literally to see through it. This makes it possible to detect in an object various internal impurities and flaws which are undetectable by other means. The transparent hologram is produced by means of an instantaneous flash of a powerful infrared laser, which is widely used in the welding and cutting of metals. The image is recorded on polymethyl methacrylate or transparent cellulose film. Infrared holography is also a good tool for the study of plasma as it is heated by laser radiation. Such plasma exists for only several millionths of a second. The accuracy of the measurements increases sharply in comparison with that of other methods. Such experiments are being conducted as part of the large-scale research program on controlled thermonuclear fusion. Infrared holography also holds promise for optics, and for inspecting the purity of materials in semiconductor technology.