A carrier-injection-based silicon micro-ring modulator is demonstrated for high-speed optical modulation. The device, optimized for small size and high modulation depth, achieves 12.5 Gbit/s modulation with an extinction ratio >9 dB. The modulator uses a silicon micro-ring resonator with a p-i-n junction embedded in a waveguide. The device's performance is enhanced by a driving scheme that improves the operation speed by reducing the carrier dynamics. The optical response time is much shorter than the electrical response time due to the nonlinear transfer function of the device, enabling faster modulation. The modulation speed is further increased by using a pre-emphasized driving signal, which reduces the charge storage time and allows for higher bit rates. Experimental results show that the modulator can support a bit rate of 12.5 Gbit/s with a high extinction ratio. The device is fabricated using e-beam lithography and is compatible with CMOS technology. The work demonstrates that carrier-injection-based silicon modulators can achieve high-speed, high-modulation-depth, and small-size operation.A carrier-injection-based silicon micro-ring modulator is demonstrated for high-speed optical modulation. The device, optimized for small size and high modulation depth, achieves 12.5 Gbit/s modulation with an extinction ratio >9 dB. The modulator uses a silicon micro-ring resonator with a p-i-n junction embedded in a waveguide. The device's performance is enhanced by a driving scheme that improves the operation speed by reducing the carrier dynamics. The optical response time is much shorter than the electrical response time due to the nonlinear transfer function of the device, enabling faster modulation. The modulation speed is further increased by using a pre-emphasized driving signal, which reduces the charge storage time and allows for higher bit rates. Experimental results show that the modulator can support a bit rate of 12.5 Gbit/s with a high extinction ratio. The device is fabricated using e-beam lithography and is compatible with CMOS technology. The work demonstrates that carrier-injection-based silicon modulators can achieve high-speed, high-modulation-depth, and small-size operation.