Optical bistability based on guided-mode resonances in photonic crystal slabs

Optical bistability of nonlinear guided-mode resonances in photonic crystal slabs (PCSs) are numerically investigated. We perform finite-difference time-domain simulations to determine the linear and nonlinear characteristics of these guided-mode resonances in PCSs. The nonlinear characteristics such as switching intensity and switching time, which are suggested as the performance metric of all-optical switches, are similar to the all-optical switches in slab waveguide gratings. While the slab waveguide gratings are sensitive to the incoming light polarization, the PCSs can offer an advantage of avoiding reduction efficiency and a requirement of careful polarization stabilization of the light source. From the calculations, we introduce a dependency of the normalized switching intensity and the switching time of the all-optical switches on quality factor for our designed guided-mode resonances in PCSs.