Abstract: Apparatus using mechanically-actuated evanascent wave coupling. At least a portion of an optical waveguide is integrated onto a substrate, and an optically active element is physically moved relatively to each other, with the result that propagation parameters for the waveguide are substantially altered. The optically active element may be a resonator or another waveguide. Altered propagation parameters can be used to cause an optical wave to be transformed in response to an electromagnetic signal. Physical parts of the apparatus can vary widely in both size and tolerance. The optically active element is mechanically actuated relative to a position of the optical waveguide.