1. H. Kogelnik and T. Li, Proc. IEEE,54, 1312 (1966).
2. D. Markuse, Theory of Dielectric Optical Waveguides, Academic Press (1974).
3. A. M. Goncharenko, Gaussian Light Beams [in Russian], Nauka i Tekhnika, Minsk (1977).
4. W. H. Garter, J. Opt. Soc. Amer.,62, 1195 (1972).
5. A. M. Goncharenko, Vestn. Akad. Nauk BelorusSSR, Ser. Fiz.-Mat. Nauk, No. 4, 82 (1974).