Figure 4: High-speed modulator characterization.

(a) The experimentally measured high-speed optical eye diagrams of the silicon electro-optic modulator driven by a terminated probe and 0.5 V_PP NRZ-OOK PRBS with a pattern length of 2³¹-1 at data rates of 10-, 15-, 20- and 25-Gb s⁻¹. The extinction ratio (ER) and insertion loss (IL) are denoted below the eye diagrams at each data rate. (b) The bit error rate curves measured for the silicon microdisk and commercial LiNbO₃ modulators, for 20- and 25-Gb s⁻¹ data rates. The bit error rate curves for the commercial LiNbO₃ modulator were used as a reference to obtain the power penalty of the silicon microdisk modulator. (c) The electro-optic frequency response of the silicon modulator.