CHARACTERISTICS ANALYSIS OF METAL-CLAD AND ABSORPTIVE DIELECTRIC WAVE-GUIDES BY A SIMPLE AND ACCURATE PERTURBATION METHOD

We present a simple and accurate method for characteristic analysis of metal-clad dielectric waveguides and absorptive waveguides. The real part N' of the complex modal index N = N' + iN" is obtained by solving the corresponding real eigenvalue equation, and the imaginary part N" is given by (partial derivative N'/partial derivative epsilon')-epsilon", where epsilon = epsilon' + i-epsilon" is the complex dielectric constant of the absorptive layer, and partial derivative N'/partial derivative epsilon' is obtained by numerical differentiation. The method is straightforward, and the cumbersome solution of complex transcendental equations is completely eliminated. Results for simple structures are in good agreement with those obtained by exact analysis.