Fig. 4
From flat to curved meta-lenses. Magnetic field intensity distribution of light transmitted through a planar a and a free-form b lens with focal of 2.5 μm. In the calculations, the incident light is a TM polarised plane wave propagating along the y-direction. Blue dashed lines indicate the interfaces. These results show that conformal boundary optics is successfully implemented in a modified FDTD numerical scheme. It offers rapid numerical testing of free-form optical devices in view of their optimisation and benchmarking with planar metasurface devices
