Fiber resonator gyroscope with low round trip loss and high output power

One embodiment is directed to a resonator fiber optic gyroscope (RFOG). The optical fiber resonator includes an optical fiber, one or more optical filters that suppresses the noise light in the resonator, one or more variable optical attenuators (VOAs) that can adjust the loss of the resonator with fast response, and one or more optical gain elements that provide amplification of light to offset part of the losses of the resonator. The RFOG also includes one or more pump lasers to produce one or more pump beams for the gain elements in the resonator and control electronics configured to control the one or more pump lasers and the one or more variable optical attenuators, such that the round-trip loss of the resonator is a substantially constant, positive value.