Electro-optical switching using coupled photonic crystal waveguides

We present an electro-optical switch implemented in coupled photonic crystal waveguides. The switch is proposed and analyzed using both the FDTD and PWM methods. The device is designed in a square lattice of silicon posts in air as well as in a hexagonal lattice of air holes in a silicon slab. The switching mechanism is a change in the conductance in the coupling region between the waveguides and hence modulating the coupling coefficient and eventually switching is achieved. Conductance is induced electrically by carrier injection or is induced optically by electron-hole pair generation. Low insertion loss and optical crosstalk in both the cross and bar switching states are predicted.