Nonlinear optical performance of periodic structures made from composites of polymers and Co3O4 nanoparticles

The nonlinear optical performance of specially designed periodic structures made from composites of optical polymers and Co3O4 nanoparticles is investigated. The refractive indices of the alternating layers are designed to be close and no photonic band gap (PBG) is formed at low power density. Under high power illumination, the index difference becomes large because of the high optical nonlinearities of the Co3O4 nanoparticles. Consequently, enhanced nonlinear optical performance is obtained with the formation and the strengthening of the PBG. Nonlinear reflection and nonlinear transmission as well as reduced nonlinear threshold are observed in the PBG structures. 2010 American Institute of Physics. [doi:10.1063/1.3486162]