Optical gain and penalty characteristics of a fiber-Bragg-grating based active optical-add-drop multiplexer

We investigate optical gain and penalty characteristics of a fiber-Bragg-grating based active optical-add-drop multiplexer (OADM). The active OADM has a two-stage structure and can amplify all the add/drop/thru channels simultaneously. The drop-channel penalty is a key parameter for the reliable operation of the active OADM. This penalty, caused mainly by multiple reflections within the active OADM, can be minimized adjusting pump powers. At the minimum drop-channel penalty, our active OADM shows fairly high optical gains as 15.5, 21, and 19.4 dB for the add, drop, and thru channels, respectively. Nevertheless, the penalties of these channels are comparable to the passive OADM.