Nonlinear responses of 2D photonic crystal waveguides

This paper focuses on the third order nonlinear response of 1D waveguide modes, and how they nonlinearly couple to 0D localized photon states. A complete analytic treatment of this problem, that allows for a complex third order susceptibility and downstream, nonresonant scattering, suggests that optical bistability should be achievable at average power levels of only a few milliwatts. Furthermore, appropriately designed waveguides can exhibit strong optical limiting behaviour as shown by experimental results. This saturated transmission of pulses from an optical parametric oscillator is due to two-photon absorption in the silicon slab used to fabricate the waveguide.