Nonlinear optical properties of copper-based photonic bandgap structures at the onset of interband transitions

We report on numerical simulations that analyze the linear and nonlinear optical properties of copper-based metal-dielectric photonic bandgap (MDPBGs) structures with transmittance passbands in the visible and nearinfrared. The nonlinear optical properties are discussed within the context of a Fermi-smearing process and simulations carried out at 570 nm, around the onset of interband transitions in Cu. Two different geometries for the realization of MDPBGs are analyzed to demonstrate that the unit cell geometry plays an important role in finding a better tradeoff between optical transparency and nonlinear optical response. It is demonstrated that compact and transparent structures can combine a maximum transmittance of 60%, passband bandwidths of 345 nm, and yield nonlinear phase shifts on the order of ΔΦ 0 = -0.010 and q0 = 0.014 cm-1 at I0 = 1 GW/cm2 for pulses in the femtosecond temporal range. © 2010 Old City Publishing, Inc.