Laser oscillation in Cr2+:ZnS waveguide thin-film structures under electrical pumping with impact excitation mechanism - N. A. Vlasenko; P. F. Oleksenko; M. O. Mukhlyo; P. M. Lytvyn; L. I. Veligura; Z. L. Denisova (Semiconductor Physics, Quantum Electronics and Optoelectronics, 2011)