A continuous multiple exposure diffraction grating (CMEDG) is fabricated holographically on polymer dispersed liquid crystal (PDLC) films using two-beam interference with multiple exposures. The grating is fabricated by exposing a PDLC film to 18 repeated exposure/non-exposure cycles with an angular step of ~10°/10° while it revolves a circle on a rotation stage. The structure of the sample thus formed is analyzed using a scanning electron microscope (SEM) and shows arc-ripples around the center. From the diffraction patterns of the formed grating obtained using a normally incident laser beam, some or all of the 18 recorded arc beams can be reconstructed, as determined by the probing location. Thus, it can be applied for use as a beam-vibration sensor for a laser.
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http://dx.doi.org/10.1364/OE.18.026300 | DOI Listing |
Cornea
January 2025
Academic Ophthalmology, School of Medicine, AU1, University of Nottingham, Nottingham, United Kingdom.
Purpose: Anterior segment optical coherence tomography (AS-OCT) is increasingly being used to complement slit-lamp biomicroscopy in the evaluation of corneal infections. Our purpose was to analyze, compare, and correlate the clinical signs elicited by these 2 methods in patients with infectious keratitis (IK).
Methods: Slit-lamp photomicrographs (diffuse and slit beam) and AS-OCT scans were obtained from 20 consecutive patients (21 eyes) with IK.
Nanomaterials (Basel)
December 2024
Department of Materials Science, Montanuniversität Leoben, 8700 Leoben, Austria.
Nanoparticles are essential for energy storage, catalysis, and medical applications, emphasizing their accurate chemical characterization. However, atom probe tomography (APT) of nanoparticles sandwiched at the interface between an encapsulating film and a substrate poses difficulties. Poor adhesion at the film-substrate interface can cause specimen fracture during APT, while impurities may introduce additional peaks in the mass spectra.
View Article and Find Full Text PDFRev Sci Instrum
January 2025
Department of Micro Engineering, Graduate School of Engineering, Kyoto University, Kyotodaigaku-Katsura C3, Nishikyo-ku, Kyoto 615-8540, Japan.
The measurement of thermal conductivities of anisotropic materials and atomically thin films is pivotal for the thermal design of next-generation electronic devices. Frequency-domain thermoreflectance (FDTR) is a pump-probe technique that is known for its accurate and straightforward approach to determining thermal conductivity and stands out as one of the most effective methodologies. Existing research has focused on advancing a measurement system that incorporates beam-offset FDTR.
View Article and Find Full Text PDFRev Sci Instrum
January 2025
HiLASE Centre, Institute of Physics of the Czech Academy of Sciences, Za Radnicí 828, 252 41 Dolní Břežany, Czechia.
We present an active alignment and stabilization control system for laser setups based on a thin-disk regenerative amplifier. This method eliminates power and pointing instability during the warm-up period and improves long-term stability throughout the entire operation. The alignment method is based on a four-mirror control system consisting of two motorized mirrors placed within the regenerative amplifier cavity, two additional motorized mirrors external to the amplifier cavity, and four camera detectors.
View Article and Find Full Text PDFBMC Cancer
January 2025
Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, Kyiv, 01601, Ukraine.
Background: nowadays, the photoacoustic imaging is in the mainstream of cancer theranostics. In this study the nanoparticles with previously proven photoacoustic imaging properties, i.e.
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