Quantum interferometric optical lithography: exploiting entanglement to beat the diffraction limit

Quantum interferometric optical lithography: exploiting entanglement to beat the diffraction limit

Boto, A.N., Kok, P., Abrams, D.S., Braunstein, S.L., Williams, C.P. and Dowling, J.P.
(2000): Physical Review Letters 85, 2733-2736 (PDF)

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.