Quantum Interferometric Optical Lithography: Exploiting Entanglement to Beat the Diffraction Limit

TLDR

Classical optical lithography is diffraction limited to writing features of size λ/2 or larger. The study demonstrates that using entangled N‑photon states, features as small as λ/(2N) can be written in an N‑photon absorbing substrate. The method employs entangled N‑photon states to achieve λ/(2N) resolution and enables arbitrary 2D patterning on an N‑photon absorbing substrate. The technique permits up to N² times more elements on a chip, and a practical N = 2 enhancement is achievable with entangled photon pairs from optical parametric down‑conversion.

Abstract

Classical optical lithography is diffraction limited to writing features of a size lambda/2 or greater, where lambda is the optical wavelength. Using nonclassical photon-number states, entangled N at a time, we show that it is possible to write features of minimum size lambda/(2N) in an N-photon absorbing substrate. This result allows one to write a factor of N2 more elements on a semiconductor chip. A factor of N = 2 can be achieved easily with entangled photon pairs generated from optical parametric down-conversion. It is shown how to write arbitrary 2D patterns by using this method.