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Non-equidistant and non-parallel grooves of a diffraction grating distort the diffracted wavefront. For a fixed wavelength, a grating with an arbitrary groove pattern is equivalent to a grating with perfect grooves having an effective surface profile different from the geometric one. It is shown that the previously proposed method for measuring non-equidistance can be used for simultaneous measurement of non-parallelism, and the measurement error is determined without any a priori information and fitting parameters. The demonstrated error (RMS) for the diffraction gratings with an aperture of 320 × 230 mm manufactured by us was 2 nm for the effective profile, 4 · 10 for non-equidistance, and 4.5 · 10 for the groove inclination angle when measuring with a spatial resolution of 0.27 mm. Rms of the wavefront distortions of the beam reflected from these gratings was 10 ± 2 nm.
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http://dx.doi.org/10.1364/OE.551097 | DOI Listing |
Nanophotonics
August 2025
Hangzhou Institute of Technology, Xidian University, 311200, Hangzhou, China.
Optically variable features are widely used in product design and anti-counterfeiting. However, current industrial methods rely heavily on chemical inks, which pose environmental concerns and suffer from poor wear and corrosion resistance. We experimentally demonstrate the generation of non-iridescent yet angle-dependent structural colors on titanium surfaces using a nanosecond laser-induced oxidation.
View Article and Find Full Text PDFNanophotonics
August 2025
Department of Electronic Engineering, Hanyang University, Seoul, 04763, Republic of Korea.
Under-display camera (UDC) systems enable full-screen displays in smartphones by embedding the camera beneath the display panel, eliminating the need for notches or punch holes. However, the periodic pixel structures of display panels introduce significant optical diffraction effects, leading to imaging artifacts and degraded visual quality. Conventional approaches to mitigate these distortions, such as deep learning-based image reconstruction, are often computationally expensive and unsuitable for real-time applications in consumer electronics.
View Article and Find Full Text PDFSci Rep
August 2025
Department of Engineering Science, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585, Japan.
Nanoparticle-polymer composite gratings incorporating ultrahigh-refractive-index hyperbranched polymers as organic nanoparticles have demonstrated exceptional light optical properties, yet their potential for neutron diffraction applications remains unexplored. We report on the neutron optical properties of a holographically structured hyperbranched-polymer-dispersed nanocomposite grating at a quasi-monochromatic neutron wavelength of 2 nm. We show that neutron diffraction measurements performed at the SANS-I instrument of the Paul Scherrer Institute (Switzerland) reveal exceptionally high neutron scattering length density modulation amplitudes.
View Article and Find Full Text PDFPhys Rev Lett
August 2025
University of Copenhagen, Niels Bohr Institute, Center for Quantum Devices, DK-2100 Copenhagen, Denmark.
In optical diffraction, the phase difference between sources in a grating or multislit mask is determined by the angle to the imaging screen, yielding the familiar multilobed diffraction image. Here, we realize a similar phenomenon in a superconductor-semiconductor hybrid circuit configured to allow Andreev scattering from multiple parallel scatterers. Phase differences between scatterers are set by tapping off of a remote superconducting meander.
View Article and Find Full Text PDFJ Synchrotron Radiat
September 2025
NSLS II, Brookhaven National Laboratory, BNL Building 703, Upton, NY 11973, USA.
We have developed a new process for the production of ultra-precise variable line spacing (VLS) lamellar diffraction gratings through nanofabrication. The process enables the fabrication of full-size X-ray gratings with sub-nanometre accuracy in groove depth, an optimal land-to-groove ratio, and uniform groove depth across the entire grating area. We also established a method for evaluating VLS groove density variation using stitched Fizeau interferometry.
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