Talbot Images of A Conical Phase Mask

In conventional Talbot lithography, only one image is employed in the photoactive layer. However, it is possible to produce two images of the phase mask in a depth-wise manner using a special phase mask. In this example, following the work of I.-H. Lee et al., a phase mask with a layer of cones is modeled in VirtualLab Fusion with the Fourier modal method (FMM, also known as RCWA). Different Talbot images are detected, such that the pillar pattern is reproduced in the primary image plane, while the hole pattern in the secondary.