Implementations disclosed herein provide for improving phase tuning efficiency of optical devices, such as a hybrid metal-on-semiconductor capacitor (MOSCAP) III-V/Si micro-ring laser. The present disclosure integrates silicon devices into a waveguide structural of the optical devices disclosed herein, for example, a waveguide resistor heater, a waveguide PIN diode, and waveguide PN diode. In some examples, the optical devices is a MOSCAP formed by a dielectric layer between two semiconductor layers, which provides for small phase tuning via plasma dispersion and/or carrier dispersion effect will occur depending on bias polarity. The plasma dispersion and/or carrier dispersion effect is enhanced according to implementations disclosed herein by heat, carrier injection, and/or additional plasma dispersion based on the silicon devices disclosed integrated into the waveguide.