This work investigates dielectric optical waveguides designed to suppress lateral leakage of TM-polarized modes, a common issue in standard rib waveguides with shallow etching. The proposed "plus-shaped" waveguide achieves this by using a vertically symmetric core structure. JCMsuite's fully vectorial finite-element eigensolver was used to compute and validate the modal properties, confirming the absence of leakage and loss for these symmetry-protected TM modes.
N. Üstün, et al. Symmetry-protected TM modes in rib-like, plus-shaped optical waveguides with shallow etching. J. Opt. Soc. Am. B, 41, 2077 (2024).
DOI: 10.1364/JOSAB.528729