Quantum entanglement for optical lithography and microscopy beyond the Rayleigh limit

Summary form only given. Recently, Boto et al. (see Phys. Rev. Lett., vol. 85, p. 2773, 2000) showed that using N entangled photons and an N-photon responsive lithographic recording medium, one could potentially write lithographic gratings with a resolution that is N times better than the classical Rayleigh criterion. An anticipated experimental difficulty is that such beams are weak, yet strong fields are needed to excite the N-photon absorption process. For the case of N=2, which was described in detail by Boto et al., we propose a method to overcome this problem. We also propose to use this idea "in reverse" to perform microscopy with better resolution than aloowed by the Rayleigh limit.