Fig. 5

a Nanograting period evolution based on the plasma interference model [72]. Copyright 2003, American Physical Society. b Schematic of nanopore-mediated interference mechanisms for describing periodicity formation in bulk and on surfaces. c Secondary field modulation induced by the coherent superposition of the scattered waves from two adjacent nanoplanes [79]. Copyright 2017, Springer Nature. d-f Theoretically calculated 3D focal-area interference field presented by the equal-phase surfaces in d) XZ plane, e XY plane, and f YZ plane. g-i Corresponding SEM images of the actually produced structures by ULSN [78]. Copyright 2021, Springer Nature