1. N. A. Gal’china, E. M. Guttsait, E. A. Dvornikov, et al., Light Eng. 21, 25 (2013).
2. Sh. Nakamura, Rev. Mod. Phys. 87, 1129 (2015).
3. A. E. Yunovich and O. I. Rabinovich, Light Eng. 22 (3), 4 (2014).
4. Zh. I. Alferov, Usp. Fiz. Nauk 172 (9), 5 (2002).
5. Cho. J. Jaehee, E. F. Schubert, and J. K. Kim, Laser Photonics Rev. 7 (3), 408 (2013).