Abstract: A device in accordance with the invention uses a novel combination of two four port optical circulators, Bragg optical fiber diffraction gratings and a single erbium-doped optical amplifier (EDFA) to implement at least dual wavelength bi-directional (single fiber) optical amplifier module. A system using an amplifier module in accordance with the invention, advantageously allows communication network managers to simultaneously reduce the cost of signal amplification hardware across a fiber optic network, increase fiber utilization, simplify field installation and maintenance operations, and maintain adherence to conventional protection philosophies such as "one system per fiber." Furthermore, the system is tolerant of unwanted effects from back reflections that may be present from a faulty optical connector or a fiber break at either end.