Implementation of sub-Rayleigh-resolution lithography using an N-photon absorber

Abstract

A nonlinear optical, phase-shifted-grating method for improving the resolution of feature sizes is implemented experimentally using an N-photon lithographic material. For the recording medium, we used poly(methyl-methacrylate) (PMMA), which is a UV lithographic material that can be excited by multi-photon absorption in the visible region. We achieved a two-fold enhancement of the resolution over the standard Rayleigh limit of half of the wavelength.