[1] Kim C H,Lee C H,Chung Y C.Bidirectional WDM self-healing ring network on simple bidirectional add-drop amplifier modules.IEEE Photon Technol Lett,1998,10(9):1340～1342

[2] Ho K P,Liaw S K. Eight-channel bidirectional WDM add/drop multiplexer. Electron Lett, 1998,34(10):947～948

[3] Shen Yunfeng, Wu Xiangnong,Lu Chao,et al.A novel single-fiber bidirectional optical add/drop multiplexer for distribution networks. OFC′01, 2001,WY5:1～3

[4] Kim Jungho,Lee Byoungho. Bidirectional wavelength add-drop multiplexer using multiport optical circulators and fiber bragg gratings.IEEE Photon Technol Lett, 2000,12(5): 561～563

[5] ITU-T Recommendation G.842, Interworking of SDH network protection architectures, ITU, 04/1997