Multimode interference optical filter for 1.3 and 1.55 μm by using taper structures

Abstract

Optimal design of optical filter for 1.3 and 1.55 mum operation based on multimode interference (MMI) structure is presented in this paper. By using taper structure at the junction between input/output waveguides, the extinction ratio (ER) and the insertion loss (IL) can be improved. Based on the defined performance factor, the optimal width and length of MMI is determined by using a modal propagation analysis and the optimal taper width is determined by performing beam propagation method.