H. Ono, K. Shimano, M. Fukutoku, and S. Kuwano, "Optical WDM node for highly-reliable AGC/ALC of EDFAs by employing power-managed control channel,"
in Optical Amplifiers and Their Applications, A. Mecozzi, M. Shimizu, and J. Zyskind, eds.,
Vol. 44 of OSA Trends in Optics and Photonics
(Optical Society of America, 2000), paper OMD3.