<p>A fiber-optic gyroscope having a depolarizer (3) installed near the fiber coil (4) and a polarizer disposed in the optical path before the light is divided in two partial lights has been proposed to avoid the fluctuation of the light power passing reversely through the polarizer induced by the rotation of the polarization plane of the light. However, since the light emitting device (1) emits a linearly polarized light, the light power first passing through the polarizer will fluctuate by the rotation of the polarization plane. This invention adds another depolarizer (2) between the light emitting device (1) and the polarizer in order to reduce or eliminate such a fluctuation. <IMAGE></p>
