Affiliation: | (1) Ulyanovsk State University, ul. Tolstogo 42, Ulyanovsk, 432970, Russia;(2) Optoelectronics Research Center, Tampere University of Technology, PO Box 692, Tampere, FIN-33101, Finland;(3) Fiber Optics Research Center, ul. Vavilova 38, Moscow, 119333, Russia |