[1] V. K. Konyukhov; Sov. Phys. Tech. Phys., 1971,15, 1283~1287.
[3] A. Papayoanou; IEEE J. Quant. Electr., 1977, QE-13, No. 1, 27~29.
[4] В. L. Abrams; IEEE J. Quant. Electr., 1973, QE-9, 940~946.
[5] D. B. HaU et al.; J. Appl. Phys., 1977, 48, No. 3, 1212~1216.
[6] Μ. В. Klein et al.; IEEE J. Quant. Electr., 1975, QE-11, 609~615.