Eight-channel add-drop microring filters are designed and fabricated by CMOS foundry technique on SOI wafer with 193 nm DUV lithography,where the microring radius are 21,20.5,20,and 19.5 μm,respectively.By measuring the transmission spectra of the through port,the transmission valleys corresponding to the resonant wavelengths of microring array are observed with the extinction ratio larger than 15 dB from 1 540 nm to 1 560 nm.The largest extinction ratio is 35 dB at the resonant wavelength of 1 ...