A new iterative method for the analysis of longitudinally invariant waveguide couplers

In this paper, a new iterative method to solve for the modal indices and field profiles of the supermodes of multichannel waveguide structures is proposed. This method combines the shift inverse power method with the simultaneous iteration method, and can be applied to any longitudinally invariant waveguide couplers problem very efficiently. Using this method, the characteristics of the leading supermodes can be obtained simultaneously. The validity and accuracy of this method are assessed by comparing to other existing methods for symmetric two-channel waveguide couplers. Results are in good agreement. Asymmetric two-channel and symmetric three-channel waveguide couplers are then considered to show the usefulness and versatility of the proposed method.<
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