An all-fiber interferometric fiber optic gyroscope having a minimum reciprocal configuration is described. The gyroscope comprises a polarized light source, a light detector, a light source coupler, a fiber optic loop coupler, and a polarization maintaining fiber optic loop. A first port of the light source coupler is counter-axially coupled to an output end of the polarized light source, and a second port of the light source coupler on the same side as the first port is coupled to the light detector. A third port on the other side of the light source coupler is counter-axially coupled to the fiber optic loop coupler, and the fiber optic loop coupler is counter-axially coupled to the polarization maintaining fiber optic loop. The light source splits the input polarized light and polarizes the optical signal propagated along a transmission arm alone, where the first and third ports are on the same transmission arm.