(a) Schematic of PC designed in this work. The dimensions are as follows: period Λ=360 nm, grating depth d=60 nm, SiO2 thickness tSiO2=300 nm, and TiO2 thickness tTiO2=160 nm. The grating width is 50% of the period. (b) Atomic force micrograph of PC fabricated by nanoreplica molding, showing the measured period of Λ=368 nm and a grating depth of d=60 nm, in good agreement with the simulated structure.