Modeled 0th and 1st-order diffraction efficiencies as the index of the layer(s) is changed. The single layer is drawn with a circle marker and the double layer gratings as a dashed line. Modeling was performed in transmission at a wavelength of λ = 1,565 nm and assumed no reflection from the backside of the silicon wafer.
Lai et al. Nanoscale Research Letters 2012 7:645 doi:10.1186/1556-276X-7-645