Fig. 2: The pattern methods of metalens based on the stepper lithography machine.
From: Review for optical metalens based on metasurfaces: fabrication and applications
a The large number of metalens’ patterns are obtained by conventional stepping method (the pattern is from single mask). b–d The large area metalens’ pattern is obtained by rotation-and-stitching method (the patterns are from serval masks). c The large area metalens’ pattern is obtained by step-and-stitching method (the patterns are from serval masks)
