80 - micron interaction length silicon photonic crystal waveguide modulator

An ultracompact silicon electro-optic modulator was experimentally demonstrated based on silicon photonic crystal (PhC) waveguides for the first time to our knowledge. Modulation operation was demonstrated by carrier injection into an $80\mu \mathrm{m}$ -long silicon PhC waveguide of a Mach-Zehnder interferometer (MZI) structure. The $\pi$ phase shift driving current, $I_{\pi }$ , across the active region is as low as $0.15\mathrm{mA}$ , which is equivalent to a $V_{\pi }$ of $7.5\mathrm{mV}$ when a $50\Omega$ impedance-matched structure is applied. The modulation depth is 92% operating at $1567\mathrm{nm}$ .