Box-like spectral response of a series-coupled microring resonant filter in a parallel channel

摘要

Formulas of the transfer functions are presented for a series-coupled microring resonant filter and the filtering characteristics of this device are investigated around the central wavelength of 1.55 μm.The simulation results show that when the number of the microring is 4,the amplitude coupling ratio between the channel and the microring is 0.25,that between two microrings is 0.022,and the flat box-like spectral response can be formed.The 3-dB bandwidth is about 0.2 nm,the insertion loss is about 1.5 dB,and the minimum of non-resonant light is close to -150 dB.