Taylor series expansion method for TM mode of polymer waveguide M-Z modulator

Mach-Zehnder waveguide is an important part in integrated optics. The transverse distribution of refractive index of polymeric ridge waveguide was calculated with the effective index method (EIM) and 3-D propagation was converted into 2-D propagation according to the structural characteristics of the polymeric ridge waveguide. Based on paraaxial scalar equation, using CrankNicholson scheme, the basic calculation scheme of Taylor series expansion method was obtained and optimized. By simulating the TM mode of a real Mach-Zehnder waveguide, the influence of various parameters on the loss was analyzed. The results show that this method is accurate, stable and easy to program.