Tribute to the Prof. V.B. Voloshinov

Vitaly Borisovich Voloshinov passed away on September 28, 2019, at the 73th year of his life. V.B. Voloshinov was an outstanding scientist well known all over the world for his research in the fields of acousto-optics, acoustoelectronics, laser physics and optical information processing. He has published more than 300 scientific papers in international journals, received 9 patents for invention. V.B. Voloshinov was the supervisor of several national and international research projects and grants (CRDF, RFBR, RSF, etc.). He has about 1800 citations of his works since 1976. Being a professor of M.V. Lomonosov Moscow State University, he has been a member of the Organizing Committee of the School on Acoustooptics and Applications for a few decades

Numerous students and young researchers will remember him as an excellent lecturer who could always explain complex problems of Physics in a clear, interesting and ingenious way. He actively participated in the popularization of the latest achievements in Physics, speaking to schoolchildren and on TV. Teaching activities of V.Voloshinov were awarded with the titles "Honored Teacher of Moscow University" and "Honorary Professor of the International Science Foundation."

The international activities of V. Voloshinov included work in research institutes in the USA, Belgium, France and other countries, participation in more than 100 international conferences not only as an invited speaker, but also as a member of the Organizing and Program Committees, the chair of sections, as well as the editor and reviewer of international journals.

Vitaly Voloshinov was born in 1947. He received an excellent education at one of the best schools in Moscow with advanced English as well as in music school. After school, Vitaly made an uneasy decision to continue his education not in music but in Physics. In 1971, he graduated from the Faculty of Physics, M.V. Lomonosov Moscow State University with honors degree and an award for the best graduation paper, carried out under the supervision of professor V. Parygin.

In 1971-1973 he worked at the Research Institute of Space Instrumentation. After that, he returned to the University and in 1977, after post-graduate course, defended his PhD thesis "Control of light beams using Bragg diffraction in an optically anisotropic medium." Since that time, V. Voloshinov’s life was connected with the Faculty of Physics of Moscow University, where he carried out a number of pioneering work in the fields of acousto-optics and acoustics of highly anisotropic crystals.

Among the most important scientific achievements of V.B. Voloshinov, the study of a special variant of acousto-optic interaction, which he called "quasi-collinear diffraction", should be mentioned first. Upon such interaction, Poynting vectors of incident light and ultrasound are collinear, while diffracted light propagates very close to this direction. This scheme of interaction made it possible to create quasi-collinear filters on the base of paratellurite crystals, possessing high spectral resolution at low control power.

New and rather unexpected patterns of propagation and reflection of acoustic waves in crystals were identified in a series of works performed jointly with N. Polikarpova. It was established that in crystals with high acoustic anisotropy, unusual phenomena are possible such as close to backward reflection of a bulk elastic wave upon its grazing incidence on a free interface crystal-vacuum, oblique incidence with an angle exceeding 90 degrees, as well as anomalous refraction, upon which a wave after passing the interface propagates at a negative angle with respect to the incident wave. The study of such phenomena is of interest both from the point of view of fundamental science, and in terms of creating new generations of devices for information processing.

The search for previously unknown physical laws was a characteristic feature of the scientific activity of V. Voloshinov. Together with his students, he was the first to study multiple Bragg diffraction in an anisotropic medium, the influence of the acoustic beam energy walk-off on the characteristics of the acousto-optic spectrum, Raman-Nath regime of anisotropic diffraction, as well as the completely unusual regime of acousto-optic interaction, which he called “semi-collinear”.

V. Voloshinov was an excellent experimenter, and he always tried to reinforce the theoretical analysis of the effects with their verification, creating experimental setups with unique characteristics. In his work style, the talent of a theoretical physicist was ideally combined with the skills of a practical engineer. Acousto-optic filters designed and manufactured in by V. Voloshinov in collaboration with his colleagues for the visible, ultraviolet (UV) and infrared (IR) spectral ranges had unique parameters, as evidenced by numerous references from researchers all over the world. In particular, he proposed and experimentally implemented a method of spectral filtering of non-polarized optical radiation and a method of spectral polarization analysis of optical images in visible, UV and IR spectral ranges with a single acousto-optic cell. A series of pioneering works was performed on acousto-optical spatial filtration of optical images with the implementation of the operations of their differentiation and integration.

Vitaly Borisovich Voloshinov was an outstanding scientist, an excellent scientific supervisor, an extremely erudite, friendly, honest and sincere person. He was not just our colleague but also a close friend for many and many people. His sudden decease is a big loss, and we would like to thank him for his presence in our life.