Optical ring-resonator-based modulators are fabricated on the silicon-on-insulator mater/a/through the mature commercial 0.8μm complementary metal oxide semiconductor foundry.The device configuration is based on a single ring resonator coupled to one bus waveguide.The waveguide widths are about 1 μm.The p-i-n junctions are employed to inject currents.The experimental result shows that the ring resonators with the quality factor of above 40000 are obtained.The maximum extinction ratio of the modulators is larger than 10dB.The speed is tens of nanoseconds, and the corresponding injected current is smaller than 10 mA.