They are nonreciprocal devices that allow light to transmit in one direction but completely suppress light propagation in the reverse direction. One prerequisite for realizing optical iso-lators is to break the Lorentz reciprocity. This paper presents a novel interferometric fiber optic gyroscope (IFOG) architecture, the Double-Sensitive Non-Reciprocal Polarization Phase Shifter IFOG (DS-NRPPS-IFOG), which introduces—for the first time—a fully passive phase biasing scheme capable of simultaneous operation at two quadrature. Fibre and bulk optical isolators are widely used to stabilize laser cavities by preventing unwanted feedback. However, due to the weak nonlinearity of traditional materials, most self-biased nonreciprocal devices are.