Peculiarity of multi-splitting filtering technology

The paper presents the review of basic results which described the optical properties of novel optical filter/multiplexer constructed by multiply coupled wave-guides. For the study, a modified effective index method (MEIM), has been used. It correctly describes, in the 2D case both the phase and the group indexes in a 3D silicon wire waveguide and makes it possible to simulate complicated SOI structures by 2D finite difference time domain method (FDTD). The silicon wire crossings are realized by means of a vertical up and down coupling through the silica buffer of tapered Si wires with the upper thick polymer waveguide. FDTD modeling prove that a short 0.26 mm multiplexer with 32 couplers has FSR 35 nm, spectral resolutions 1.4 nm, internal loss -0.7 dB and sidelobes -20 dB.