1. Kurdyubov, A.S., Trifonov, A.V., Gerlovin, I.Ya., Ignatiev, I.V., and Kavokin, A.V., Phys. Solid State, 2017, vol. 59, no. 7, p. 1298.
2. Zhang, X.-C. and Xu, J., Introduction to THz Wave Photonics, New York: Springer, 2010, p.49.
3. Lee, Y.-S., Principles of Terahertz Science and Technology, New York: Springer, 2009, p.166.
4. Knyazev, B.A. and Kuz’min, A.V., Vestn. Novosib. Gos. Univ. Ser. Fiz., 2007, vol. 2, no. 1, p. 108.