A fiber optic gyroscope includes an optical fiber coil, optical circuit, and optical gate. The optical circuit receives input optical signals generated by an optical source, splits each input optical signal into first and second optical signals, phase modulates one or both of the first and second optical signals, transmits the first and second optical signals to the optical fiber coil such that the first and second optical signals counterpropagate through the optical fiber coil, receives the first and second optical signals after counterpropagating through the optical fiber coil, combines the first and second optical signals after counterpropagating through the optical fiber coil, and transmits the combined first and second optical signals to a photodetector. The optical gate controllably time modulates the input optical signals and/or the first and second optical signals prior to being combined, said time modulating synchronized with said phase modulating.