Application of terahertz Gouy phase shift from curved surfaces for estimation of crop yield.

@article{Federici2009ApplicationOT,
  title={Application of terahertz Gouy phase shift from curved surfaces for estimation of crop yield.},
  author={John F. Federici and Robert L. Wample and David E. Rodriguez and Suman Mukherjee},
  journal={Applied optics},
  year={2009},
  volume={48 7},
  pages={
          1382-8
        }
}
The application of terahertz time-domain spectroscopy (THz-TDS) and imaging to differentiate flat and curved surfaces in reflection via the THz Gouy phase shift is demonstrated. For a THz-TDS system that is aligned for reflection from a flat surface, the presence of a curved surface displaces the image focal plane from the detector plane, resulting in a Gouy phase shift. The potential of utilizing this configuration for estimating the number and size of curved objects is discussed with… 
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