[1] Chen Y K, Hu C J, Lee C C at al.. Low-crosstalk and compact optical add-drop multiplexer using a multiport circulator and fiber Bragg gratings. IEEE Photon. Technol. Lett., 2000, 12(10):1394~1396
[3] Se Yoon Kim, Sang Bae Lee, Seo Won Kwon at al.. Channel-switching active add/drop multiplexer with tunable gratings. Electron. Lett., 1998, 34(1):104~105
[4] Goldstein E L, Eskildsen L, Elrefaie A F. Performance implications of component crosstalk in transparent lightwave networks. IEEE Photon. Technol. Lett., 1994, 6(5):657~660