We must stress once again that the use of the plasma (recombination) principle is most promising in two situations: (a) in the development of high power high-energy lasers; (b) in the generation of shorter wavelengths (vacuum ultraviolet and x-ray region). These two directions of the development of laser physics are currently of greatest interest but the experiments are still being carried out on the basis of the theory of gas lasers rather that plasma lasers. It seems to us that the adoption of recombination ideas will help in many ways.
The theory of plasma lasers is currently held up by the absence of information on the cross sections of elementary events. Even in the case of electron collisions with excited atoms of simple electronic structure (H, He, Li, Na), there are practically no experimental data and it is not clear how reliable are the theoretical calculations. The situation is even worse in the case of parameters of chemical reactions in which excited atoms and molecules participate. This lack of information is holding up progress in many aspects of the theory of plasma lasers. Therefore, it is desirable not only to try to build high-power lasers and lasers emitting shorter wavelengths but also to extend considerably systematic studies of the rates of elementary events occurring in such lasers.