Nonlinear Double-Layer Bragg Waveguide: Analytical and Numerical Approaches to Investigate Waveguiding Problem

Figure 7

Case 2(a). The inner radius 𝑅₁=2. Marked eigenvalues: linear eigenvalue 𝛾≈2.524 (red dot 𝛾²≈6.370) and nonlinear eigenvalues 𝛾≈2.571, 𝛾≈3.142, and 𝛾≈3.806 (green, blue, and black dots, resp., 𝛾²≈6.610, 𝛾²≈9.872, and 𝛾²≈14.486).