Nonlinear optics of gaseous media: breakthrough into ultrashort pulse region and use of new spectral regions

New research trends in modern physics that have emerged due to progress in ideas and technology based on studies and use of nonlinear optical processes in excited and ionized gaseous media are discussed. An outlook of the use of these processes for frequency conversion, ultrashort pulses generation and development of new methods of nonlinear spectroscopy and nonlinear optical analysis is given.