In the intervening years since the publication of Volume I, the develop­ ment of new uses for the various types of lasers has proceeded at a rate more rapid than even the most fanciful dreamers envisioned. Of course, the main effort has been on the laser itself-new wavelengths, shorter and longer time domains for pulses, increases in power, and, most important, greater reliability. In its first stage the laser was described as a solution in search of a problem. The production of holograms was one problem whose solution seemed to involve large number of lasers. However that proposal had its own difficulties, for the hologram itself was described as a solution searching for a problem. But all of that now is a chapter from ancient history . On the current scene the laser is used in industrial pro­ duction lines, as a classroom item at all levels of education, and in com­ mercial usage such that the public is generally exposed to the laser devices themselves. Trial runs have been made, e. g. , of laser-based supermarket checkout devices and as commercial exploitation of this item begins, cer­ tainly many more similar adaptations will follow. However, the shift in emphasis from research usage of lasers to de­ velopment and production has been relative rather than absolute. The use of the laser in research has not lessened; rather it has grown at as fast a pace. Yet a similar trend is seen there also.