We report a high beam quality continuous-wave (CW) 320 nm ultra-violet (UV) laser. An end-pumped praseodymium-doped yttrium lithium fluoride (Pr:YLF) laser is constructed in a typical V-shaped cavity structure, while the UV output is obtained through intracavity frequency doubling using (LBO). We investigate the dependence of the UV output power, as well as the spot profile on the LBO length, and find that the "walk-off" within LBO severely affects both the frequency-doubling efficiency and the beam quality of the UV output. Rotated twin LBO crystals are then applied to substitute for single long LBO crystal to compensate the walk-off effect, resulting in high-power 320 nm output up to 410 mW under the absorbed pump power of 4.0 W at 444 nm, with a high beam quality of 2=1.02 and 2=1.04.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/AO.522760 | DOI Listing |
In image-guided radiotherapy (IGRT), four-dimensional cone-beam computed tomography (4D-CBCT) is critical for assessing tumor motion during a patients breathing cycle prior to beam delivery. However, generating 4D-CBCT images with sufficient quality requires significantly more projection images than a standard 3D-CBCT scan, leading to extended scanning times and increased imaging dose to the patient. To address these limitations, there is a strong demand for methods capable of reconstructing high-quality 4D-CBCT images from a 1-minute 3D-CBCT acquisition.
View Article and Find Full Text PDFJ Med Imaging (Bellingham)
January 2025
U.S. Food and Drug Administration, Office of Science and Engineering Labs, Division of Imaging, Diagnostics, and Software Reliability, Silver Spring, Maryland, United States.
Purpose: We evaluate the impact of charge summing correction on a cadmium telluride (CdTe)-based photon-counting detector in breast computed tomography (CT).
Approach: We employ a custom-built laboratory benchtop system using the X-THOR FX30 0.75-mm CdTe detector (Varex Imaging, Salt Lake City, Utah, United States) with a pixel pitch of 0.
Appl Radiat Isot
January 2025
Department of Medical Physics, Copernicus Memorial Hospital in Lodz Comprehensive Cancer Center and Traumatology, Lodz, Poland; Department of Medical Imaging Technology, Medical University of Lodz, Ul. Lindleya 6, 90-131, Łódź, Poland.
In this study, ten recovered water samples were analysed using gamma spectrometry and Liquid Scintillation Counting techniques for identification of radioactive impurities (quality and quantity) and for radioactive waste qualifications. The presence of several radioactive isotopes of H, Co Mn in the recovered [O] water irradiated with 11 MeV protons used to produce [F] fluoride by the O(p,n)F reaction has been confirmed. Radioactive impurities were generated directly in enriched water or washed out from activated Havar foil, or tantalum body target material.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Engineering Research Center of Optical Instrument and System, Ministry of Education and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No.516 Jungong Road, Shanghai, 200093, China.
Background: Surface-enhanced Raman scattering (SERS) has attracted much attention as a powerful detection and analysis tool with high sensitivity and fast detection speed. The intensity of the SERS signal mainly depended on the highly enhanced electromagnetic field of nanostructure near the substrate. However, the fabrication of high-quality SERS nanostructured substrates is usually complicated, makes many methods unsuitable for large-scale production of SERS substrates.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
CNR-IOM-Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, 34149 Trieste, Italy.
Hybrid systems consisting of highly transparent channels of low-dimensional semiconductors between superconducting elements allow the formation of quantum electronic circuits. Therefore, they are among the novel material platforms that could pave the way for scalable quantum computation. To this aim, InAs two-dimensional electron gases are among the ideal semiconductor systems due to their vanishing Schottky barrier; however, their exploitation is limited by the unavailability of commercial lattice-matched substrates.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!