Capacitor-embedded 054 pJ/bit silicon-slot photonic crystal waveguide modulator

A high-speed compact silicon modulator based on the lateral capacitor configuration is experimentally demonstrated with low-power consumption and $3\mathrm{dB}$ modulation depth. The capacitor layout is introduced to scale down the total modulator capacitance to $30\times {10}^{-15}\mathrm{F}$, which effectively reduces the rf power consumption to $0.54\mathrm{pJ}∕\text{bit}$. Exploiting the slow group velocity of light in the slot photonic crystal waveguides, the device reported herein exhibits higher modulation efficiency than conventional capacitor modulator and provides a $V_{\pi }L$ figure of merit of $0.18\mathrm{V}\mathrm{cm}$ at the wavelength of $1548\mathrm{nm}$.