title: Comparison of numerical simulation on active rectangular waveguide couplers by vector, scalar finite element, and effective refractive index methods.
abstract: We compare the vector finite element, scalar finite element, and effective refractive index methods for the calculation of the modal properties of active rectangular waveguide couplers. We find that the scalar finite element method is highly reliable when the refractive index difference between the core and the cladding is <15% and/or for large aspect ratios. We also find that the effective refractive index method is particularly difficult to use in treating active waveguides.
authors.forename: K
authors.initials: K
authors.lastname: Hayakawa
authors.forename: K
authors.initials: K
authors.lastname: Sakuda