Electro-optically switched compact coupled photonic crystal waveguide directional coupler

In this paper, we present a compact photonic crystal directional coupler in a silicon on insulator platform electro-optically switched at 150 kHz with a switching time of 620 ns under a low voltage operation of 2.9 V. The switch design utilizes a coupled photonic crystal structure designed to operate in the slow light regime. Switching is attained by modulating the coupling coefficient of the coupled photonic crystal waveguide system by using a p-i-n diode to modulate the carrier concentration with a density of ∼104 A/cm2 across the plane of the photonic crystal.