A planar lightwave circuit (PLC) add-drop filter is proposed and analyzed, which consists of a symmetric Mach-Zehnder interferometer (MZI) combined with double microring resonators. A critical coupling condition is derived for a better box-like drop spectrum. Comparisons of its characteristics with other schemes, such as a MZI with a single ring resonator, arepresented, and some of the issues about device design and fabrication are also discussed.
© 2005 Chinese Optics Letters
Fufei Pang, Xiuyou Han, Haiwen Cai, Ronghui Qu, and Zujie Fang, "Characteristics of an add-drop filter composed of a Mach-Zehnder interferometer and double ring resonators," Chin. Opt. Lett. 3, 21-23 (2005)