Abstract

Semiconductor rib waveguides are the most basic components for integrated optics. Hence, their modeling and analysis are essential for the successful realization of photonic integrated circuits. For this purpose the so called beam propagation method employing fast-Fourier-transform(FFT) has widely been used to analyze single , coupled, and branching rib waveguides[1][2]. We will refer to this technique as FFT-BPM from now on. The accuracy of FFT-BPM is well demonstrated in comparison with the results of other methods of analysis[3]. However, it is well known that very small propagating step sizes are required for the accurate FFT-BPM analysis of a waveguide with a rapidly varying index profile such as a semiconductor rib waveguide. Recently, D. Yevick et al[6][7] developed several efficient beam propagation techniques for the analysis of semiconductor rib waveguides, which employ split step finite difference algorithm or direct multiplications by block-diagonal matrices for homogeneous propagation operator. In this paper, a new and very efficient BPM, abbreviated as EFD-BPM, is described. EFD-BPM utilizes an explicit finite difference algorithm, where partial derivatives in the paraxial wave equation are approximated using finite differences. This new method is applied to the analysis of single, coupled, and Y-junction semiconductor rib waveguides to demonstrate its accuracy and efficiency.

© 1990 Optical Society of America