Submicroscopic pattern replication with visible light

Contact imaging with visible light is possible at submicroscopic resolution because the near field of a radiating object contains information of sufficiently high resolution. In this paper we demonstrate this principle by contact imaging of planar submicroscopic metal patterns with blue light (400 nm). Experimental details are described for two experiments: (1) The shadow of an opaque pattern was recorded on a negative photoresist and developed using permanganate staining. (2) An image of a transparent metal pattern was imprinted onto a molecular dye layer, exploiting the fact that photochemical bleaching of the dye is inhibited by contact with the metal due to energy transfer. Development was by silver decoration. The resolution obtained was 100 nm with the photoresist, and 50 to 70 nm with the dye layer.