In this work, we report on the observation of the electric field-induced linear electro-optical effect in a silicon-based slot waveguide ring resonator covered by the nonlinear optical polymer Poly[(methyl methacrylate)-co-(Disperse Red 1 methacrylate)]. The device is fabricated in a photonic integrated circuit technology and intensity modulation is demonstrated to work in a direct-detection setup. As unique feature, the electric field-induced linear electro-optical effect allows to modulate the optical carrier wave with a time-varying electric field, while a static electric field can control its amplitude with no need for additional photonic components. Here, a linear tuning of the modulation-amplitude as function of the applied static electric field is demonstrated. This work paves a way toward novel integrated photonic device concepts.