Imaging the irradiance distribution in the optical near field

This letter describes the use of a sensitive photoresist for direct imaging of optical intensity profiles in near-field photolithographic experiments. A comparison between experimental patterns in exposed, developed photoresist and calculated profiles of intensity shows that this procedure provides a reliable semiquantitative image of the irradiance distribution in the near field; experiment and theory correlate adequately. A potential use of the superficial diffraction contrast recorded in photoresist as the basis for a new method of the fabrication of nanostructures is discussed.