Eigenanalysis of photonic structures based on finite element with efficient suppression of spurious modes

The establishment of finite element based eigenanalysis as a numerical tool for the indepth understanding and revealing the characteristics of Terahertz and photonic structures, constitute the scope of this work. A tree-cotree splitting formulation method is used for the removal of imaginary and dc spurious modes. The Ritz vectors are appropriately restricted during the linearization technique of the polynomial eigenproblem. The capabilities of the method are demonstrated presenting certain microdisk and microrings whispering gallery modes eigenvalues and eigenvectors.