Acousto-optics as a field of current interest in research and application

Some personal recollections on the acousto-optics as an interesting field of physics and its applications will be shared with the participants in a short welcome address. The consecutive number of the present Spring School on AO and A, 14-th, indicates a long history of events (39 years) initiated in 1980 by the University of Gdańsk as the triennial international meeting of specialists of science and technology over the world, being continued till now.The fundamentals of the acousto-optics domain covering light (fotons) and ultrasonics (fonons) interactions originally come from works of L. N. Brillouin whose anniversaries the 130 years of his birthday and the 50 years of his death are being celebrated during the current year. The next principles were widely developed by many others in 1930’s after essential two independent papers by P. Debye and F. W. Sears (USA) and R. Lucas and P. Biquard (France), then fundamentals by C.V. Raman and N. S. Nagendra Nath, followed by many papers and applications after the II World War. The wide and rich literature of the subject of the last 100 years built up a branch of knowledge to which a piece of contribution of the AO and A Schools has its own place. The further development of the branch is prospective, too. Recently, such problems as very short time (pico- and femtoseconds) acousto-optic interactions, nonlinear processes in bio- and nano-structures and their applications in acousto-optic and optoelectronic instrumentation as well as many others are subjects of the current interest and promising topics for the future.