A scheme for high-quality nonlinear all-optical switches

The weak material nonlinearity and the high precision requirement for high-quality resonances are the two most critical hurdles in the design of all-optical switches. It is shown that, when the guided-mode has a very small wave vector component normal to the guiding layer, the guided-mode resonance (GMR) is robust against the structure parameters. Meanwhile, the corresponding GMR is very sensitive to the modulations of both the incident wavelength and the permittivity of the guiding layer. The GMR then features easy-control, high-quality and permittivity-sensitive. Based on such configuration, low-threshold all-optical switches working between zero- and total-transmission are realized.