Approximate analytic solutions of the leaky modes in two-dimensional slab waveguides are derived through an asymptotic analysis. General slab waveguides with three layers of possibly different refractive indexes are studied for both the transverse electric (TE) and transverse magnetic (TM) cases. The results are useful in the eigenmode expansion method, where the leaky modes appear if a perfectly matched layer (PML) is used to terminate the transverse directions of optical waveguides.
© 2006 IEEE
Jianxin Zhu and Ya Yan Lu, "Leaky Modes of Slab Waveguides—Asymptotic Solutions," J. Lightwave Technol. 24, 1619- (2006)