Embodiments of the present disclosure are directed towards a micro-electromechanical system (MEMS) sensing apparatus, including a laser arrangement configured to generate a light beam, a first waveguide configured to receive and output the light beam, and a second waveguide aligned endface to endface with the first waveguide. The second waveguide may be configured to receive at least a portion of the light beam from the first waveguide via optical coupling through the aligned endfaces. Either the first or second waveguide may be configured to be moveable in response to an inertial change of the apparatus, wherein movement of the first or second waveguide causes a corresponding change in light intensity of the portion of the light beam, the change in light intensity indicating a measure of the inertial change. Other embodiments may be described and/or claimed.