An all-optical switching device is a crucial component for developing high speed data transmission and signal processing
in telecommunication network. The device is based on
nonlinear optical material, whose refractive index depends on light intensity. Various concepts for all-optical switching devices have been studied; however as the best of our knowledge, until now there is no purely optical switching devices have been realized. Recently, photonic crystals have been considerable interest both theoretically and experimentally for switching devices. Due to the practical reason, we studied one-dimensional nonlinear photonic crystal for all-optical switching devices. We use transfer matrix method and nonlinear coupled mode
equation to determine photonic bandgap and optical switching process. We applied both methods to three different structures: nonlinear Distributed Bragg Reflector (DBR), photonic crystal with defect layer and nonlinear photonic crystal which has similar linear refractive index but has different sign of nonlinear refractive index. By using an appropriate combination of refractive indices, it was found that the first two structures can be used as all-optical switching in telecommunication wavelength (1.55µm). The third structure can be used both for switching and optical limiter at the wavelength of 1.0 µm.