Gain characterization of all-optical gain-clamped PDFFA for WDM networks using the feedback theory

Using feedback theory, we analyze the gain of an all-optical gain-clamped p raseodymium-doped fluoride fiber amplifier (AOGC PDFFA) for eight-channel m ultiwavelength operation. We demonstrate by numerical simulation that gain stabilization is achieved when the open-loop gain is higher than the feedba ck path attenuation. Tf this condition is fulfilled, the gain stabilizes to a value equal to the feedback path attenuation and is not influenced by th e pump power, input signal power, number of channels, doped fiber length, o r any other doped fiber parameter. In our setup the AOGC PDFFA noise figure is 0.12 dB lower than the open-loop PDFFA noise figure.