Phaseless 3D Optical Nanoimaging
A.A. Govyadinov, G.Y. Panasyuk, J.C. Schotland
We have developed a new method for 3D nano-imaging that does not rely on optical phase measurements or phase-controlled illumination. As a proxy for the optical phase, we introduce a controlled scatterer, such as an atomic force microscope tip, into the near-field of the sample. The power extinguished from the incident light beam, which illuminates both the sample and the tip, is then measured. Changing the tip’s position controls the pattern of illumination and thus modifies the extinguished power. The 3D structure of the sample can then be reconstructed from data that are collected as the tip scans a three-dimensional space above the sample. The readily available sub-nanometer precision in probe positioning that is achievable in atomic force microscopy, in combination with the simplicity of far-field measurements of the extinguished power, is expected to allow the practical realization of the proposed method.
Physical Review Letters 103, 213901 (2009)