[1] D. Botez, IEE Proc., 6, 23 (1982)
[2] S. Wang et al., IEEE J. Quant. Electr., QE-17, 453 (1981)
[3] E. G. Hunsperger, "Integrated Optics: Theory and Technology", 2nd edition (Springer-Verlay, Berlin, Heidelberg, New York, Tokyo), 1984
[5] Ο. Ζ. Guo et al., IEEE J. Quant. Electr., QE-21, 794 (1985)
[7] N. Chinone, J. Appl. Phys., 48, 3237 (1977)
