Abstract: A method of forming a photonic inertial sensor includes providing a substrate having an insulation layer and a silicon layer on the insulation layer opposite the substrate; etching the silicon layer to form a silicon proof mass for the photonic inertial sensor; etching at least a portion of the insulation layer underneath the silicon proof mass to suspend the silicon proof mass; and depositing a high-density mass-increasing layer on the silicon proof mass to thereby increase the mass of the silicon proof mass.