DESIGN AND ANALYSIS OF NOVEL MULTIMODE OPTICAL FILTERS IN DIELECTRIC WAVE-GUIDE

A new multimode filter design for wavelength multiplexing / demultiple xing applications is investigated. An asymmetric bend generates a numb er of higher-order modes with appropriate amplitudes from a single-mod e incident wave containing two wavelengths. These modes, after travell ing along a straight section of multimode waveguide, are recombined in the output Y-branch in such a way that the optical signals at two wav elengths are split and redirected toward different output branches. Th e structure is analyzed by a combination of finite-difference / time-d omain (FD / TD) procedure and a recently developed physical optics met hod. Numerical results on a sample structure are presented and issues related to the accuracy of results are addressed.