We propose a method for designing refractive optical elements for collimated beam shaping in the geometrical optics approximation. In this method, the problem of finding a ray mapping is formulated as a linear assignment problem, which is a discrete version of the corresponding mass transportation problem. A method for reconstructing optical surfaces from a computed discrete ray mapping is proposed. The method is suitable for designing continuous piecewise-smooth optical surfaces. The design of refractive optical elements transforming beams with circular cross-section to variously shaped (rectangular, triangular, and cross-shaped) beams with plane wavefront is discussed. The presented numerical simulation results confirm high efficiency of the designed optical elements.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/OE.26.024602 | DOI Listing |
Light Sci Appl
January 2025
Institute for Photon Science and Technology, The University of Tokyo, Tokyo, Japan.
Light manipulation and control are essential in various contemporary technologies, and as these technologies evolve, the demand for miniaturized optical components increases. Planar-lens technologies, such as metasurfaces and diffractive optical elements, have gained attention in recent years for their potential to dramatically reduce the thickness of traditional refractive optical systems. However, their fabrication, particularly for visible wavelengths, involves complex and costly processes, such as high-resolution lithography and dry-etching, which has limited their availability.
View Article and Find Full Text PDFFood Chem
January 2025
Group of Alternative Analytical Approaches (GAAA), Bioenergy Research Institute (IPBEN), Institute of Chemistry, São Paulo State University (UNESP), Araraquara, 14800-060 São Paulo State, Brazil; National Institute of Alternative Technologies for Detection Toxicological Assessment and Removal of Micropollutants and Radioactive Substances (INCT-DATREM), Araraquara, 14800-060 São Paulo State, Brazil. Electronic address:
Non-conventional food plants (or non-conventional edible plants) have the potential to serve as an excellent nutritional alternative while promoting the circular economy. Given the nutritional potential of non-conventional food plants, this study aimed to investigate and determine the composition of these plants using inductively coupled plasma optical emission spectroscopy (ICP OES) combined with chemometric techniques. In this context, the following non-conventional food plant species were evaluated: serralha (Sonchus oleraceus), two species of ora-pro-nóbis, Pereskia grandifolia and Pereskia aculeata, peixinho (Nematanthus gregarius), alfavaca (Ocimum basilicum), taioba (Xanthosoma sagittifolium), capeba (Pothomorphe umbellata), tranchagem (Plantago major), and bardana (Arctium lappa).
View Article and Find Full Text PDFAnal Chem
January 2025
College of Chemistry and Material Science, Northwest University, Xi'an 710127, China.
With rapid, energy-intensive, and coal-fueled economic growth, global air quality is deteriorating, and particulate matter pollution has emerged as one of the major public health problems worldwide. It is extremely urgent to achieve carbon emission reduction and air pollution prevention and control, aiming at the common problem of weak and unstable signals of characteristic elements in the application of laser-induced breakdown spectroscopy (LIBS) technology for trace element detection. In this study, the influence of the optical fiber collimation signal enhancement method on the LIBS signal was explored.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon 16419, Republic of Korea.
Optical resolution photoacoustic imaging of uneven samples without z-scanning is transformative for the fast analysis and diagnosis of diseases. However, current approaches to elongate the depth of field (DOF) typically imply cumbersome postprocessing procedures, bulky optical element ensembles, or substantial excitation beam side lobes. Metasurface technology allows for the phase modulation of light and the miniaturization of imaging systems to wavelength-size thickness.
View Article and Find Full Text PDFSci Transl Med
January 2025
Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder. Antiamyloid antibody treatments modestly slow disease progression in mild dementia due to AD. Emerging evidence shows that homeostatic dysregulation of the brain immune system, especially that orchestrated by microglia, plays an important role in disease onset and progression.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!