Abstract: A reconfigurable AGC loop design for an optical amplifier with a software provisional switch in the AGC loop inside the optical amplifier is disclosed. On the input side, there is a 1×m switch for switching a first input to the input of an optical amplifier, or to route other external pins to the optical amplifier. On the output side, there is a 1×n switch for switching a first output to the output of an optical amplifier, or to route other external pins to the optical amplifier. The AGC loop inside an optical amplifier is available to operate with other external signals. This reconfigurability unleashes the AGC loop capability that is traditionally confined to individual optical amplifier, provides flexibility, and greatly simplifies the design of optical node.