The optical includes a waveguide positioned on a base and an optical component positioned on the base. The optical component is a light sensor that includes an active medium or a modulator that includes an active medium. The waveguide is configured to guide a light signal through the component such that the light signal is guided through the active medium. The device includes one or more heat control features selected from the group consisting of: placing one or more thermal conductors over a lateral side of a ridge of the active medium; extending thermal conductors from within the active component to a location outside of the active component, and tapering the ridge of the active medium within the perimeter of the active component.