Elimination of spurious modes in full-vectorial finite element method based acoustic modal solution

Abstract

Citation: Gulistan, A., Rahman, M. M., Ghosh, S. ORCID: 0000-0002-1992-2289 and Rahman, B. M. ORCID: 0000-0001-6384-0961 (2019). Elimination of spurious modes in fullvectorial finite element method based acoustic modal solution.This is the published version of the paper.This version of the publication may differ from the final published version.Permanent repository link: http://openaccess.city.ac.uk/22191/ Link to published version: http://dx.Abstract: Finite element method is a powerful technique for solving a wide range of engineering problems. However, the existence of the spurious solutions in full-vectorial finite element method has been a major problem for both acoustic and optic modal analyses. For emerging photonic devices exploiting light-sound interactions in high index contrast waveguides, this problem is a major limitation. A penalty function is introduced to remove these unwanted spurious modes in acoustic waveguides, which also identifies the acoustic modes more easily. Numerically simulated results also show considerably improved vector mode profiles. The proposed penalty method has been applied for the characterization of low index contrast single mode fiber and also for high index contrast silicon nanowire to demonstrate its effectiveness.

Spectral Element Method for the Elastic/Acoustic Waveguide Problem in Anisotropic Metamaterials

“…Incidentally, no impurity is present in our contour maps in Fig. 9, which indirectly indicates that no spurious modes exist in our method as discussed in 40 . In addition, there are convincing explanations for the spurious modes.…”

“…(1) Normal Elastic Materials First, to verify the accuracy of the SEM solver for the inhomogeneous open waveguide problems, we conduct a numerical experiment on the actual optical quartz fiber model consisting of cladding 1 and core 1, and the frequency is chosen as 3 GHz as in realistic application 40 . The agreement among the three results in Table 7 verifies the accuracy of our scheme.…”