A. R. Baev
Institute of Applied Physics of the National Academy of Science of Belarus
Belarus

Address for correspondence:
Baev A.R. –
Institute of Applied Physics of the National Academy
of Science of Belarus,
Akademicheskaya str., 16, Minsk 220072, Belarus
 e-mail: baev@iaph.bas-net.by

A. I. Metskovets
Institute of Physics of the National Academy of Science of Belarus
Belarus

Nezavisimosty Ave., 68, Minsk 220072

A. L. Mayorov
Institute of Applied Physics of the National Academy of Science of Belarus
Belarus

Akademicheskaya str., 16, Minsk 220072

M. V. Asadchaya
Institute of Applied Physics of the National Academy of Science of Belarus
Belarus

Akademicheskaya str., 16, Minsk 220072

A. V. Vorobey
Institute of Applied Physics of the National Academy of Science of Belarus
Belarus

Akademicheskaya str., 16, Minsk 220072