We consider an imaging problem that aims to identify the profile of a reflective surface by the scattered wave measured in the near field. Potential applications include nondestructive detection of micro devices, subwavelength imaging techniques in nano-optics. When the height of the imaging target is small, the connection between the localized evanescent wave modes of the measurement and the high spatial frequency components of the structure is characterized explicitly, which leads to a natural reconstruction method with super resolution images. A novel multiple frequency approach is also presented that captures both the main features as well as the fine details of the structure.
© 2012 Optical Society of AmericaFull Article | PDF Article