Analytical expressions of the guided mode field distribution: analysis and comparison

Methods for determining the parameters of the three different approximate solutions for the fundamental mode field distribution of Ti:LiNbO/sub 3/ optical waveguides by using the variational technique are presented. This analysis gives closer approximation not only to the field distribution, but also to the propagation constant. Comparison with the exact results for the exponential index distribution in depth shows that these trial functions are closer to the real solution. It is also shown that these solutions are as accurate as the effective index method for Ti:LiNbO/sub 3/ strip waveguides. The analysis provides an approach for comparing and assessing these solutions.<
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