Accessing the optical limiting properties of metallo-dielectric photonic band gap structures

The optical limiting properties of a one-dimensional, transparent metallodielectric photonic band gap structure are studied. Due to light confinement in the structure that enhances the nonlinear response of the layers, a nonlinear transmission dependence on the incident light intensity is found. Experimental results are reported for a four period sample where the single period consists of ZnO and Ag layers 109 and 17 nm thick, respectively. The structure was designed to exhibit a transmission resonance at 532 nm. Under the action of a Q-switched frequency doubled Nd:yttrium–aluminum–garnet laser, a decrease in transmission of approximately 50% is obtained for a maximum incident light intensity of 2 GW/cm2. These results are explained in terms of a dynamic change of the absorption coefficient due to the enhancement of the two-photon absorption process. These results suggest that the structure is suitable for optical limiting applications in the visible range