Near-field diffraction of fs and sub-fs pulses: super resolution of NSOM in space and time

The diffraction of fs and sub-fs pulses by a nm-size slit-type aperture in a thick perfectly conducting screen and its implication for near-field scanning optical microscopy (NSOM) is analyzed. The results theoretically demonstrate the feasibility of a NSOM with rim-scale resolution in space together with fs-scale resolution in time. The further increase of simultaneous resolution in space and time is limited by the spatial and temporal broadening of the diffracted pulse and the decrease of the screen opacity. (C) 2003 Elsevier B.V. All rights reserved.