Publications by authors named "Hidemitsu Toba"
It has been shown in previous literature that nearly diffraction limited focusing is possible by a doublet metalens up to almost 30 deg. This result indicates that metalenses can work well, even at oblique incidence. Although various meta-atoms have been proposed, as far as we know, there is no report that compares what kind of meta-atom is robust against oblique incidence.
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- The proposed model-based fringe analysis technique enhances the traditional Fourier transform method for analyzing dense fringe patterns, particularly those with large phase variations.
- Conventional Fourier methods struggle with a limited dynamic range due to broadening of the Fourier spectra, making it hard to distinguish phase shifts.
- The new iterative technique successfully narrows the spectrum and minimizes phase errors, with simulation and experimental results supporting its effectiveness for high-density fringe patterns.
Nyquist sampling theorem in an image calculation with angular spectrum method restricts a propagation distance and a focal length of a lens. In order to avoid these restrictions, we studied suitable expressions for the image computations depending on their conditions. Additionally, a lateral scale in an observation plane can be magnified freely by using a scaled convolution in each expression.
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