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This work presents an innovative exploration of generating and modulating off-axis photonic nanojets (PNJs) using gradient refractive index (GRIN) microcylinders with asymmetric profiles. The modulation effects of refractive index gradient, average refractive index, environmental factors, and microcylinder rotation on off-axis PNJ properties are systematically investigated. Results show that the refractive index gradient is the core parameter for controlling PNJ deflection angles: increasing the gradient enhances off-axis displacement while reducing peak intensity and extending decay length. The average refractive index primarily influences PNJ spatial distribution, with higher values creating more compact jets and stronger field intensities. Dynamic modulating of off-axis PNJ is achieved by rotating the GRIN orientation. In low-refractive-index-contrast liquid environments, PNJs exhibit abnormal phenomena such as curved beams, revealing significant environmental influences. This work expands the control dimensions of PNJs beyond traditional axial constraints, providing new, to the best of our knowledge, solutions for multi-angle optical detection, optofluidic tweezers, and micro/nano-fabrication.
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http://dx.doi.org/10.1364/OL.564490 | DOI Listing |
J Appl Clin Med Phys
September 2025
Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
Background: The impact of beam dosimetry changes brought on by target degradation has not been well investigated.
Purpose: To determine the optimal dosimetry metrics for detecting target degradation and to investigate the impact of beam dosimetry changes brought on by target degradation.
Methods: The EGSnrc Monte Carlo programs were used to model the Varian Novalis Tx linear accelerator.
This work presents an innovative exploration of generating and modulating off-axis photonic nanojets (PNJs) using gradient refractive index (GRIN) microcylinders with asymmetric profiles. The modulation effects of refractive index gradient, average refractive index, environmental factors, and microcylinder rotation on off-axis PNJ properties are systematically investigated. Results show that the refractive index gradient is the core parameter for controlling PNJ deflection angles: increasing the gradient enhances off-axis displacement while reducing peak intensity and extending decay length.
View Article and Find Full Text PDFSensors (Basel)
July 2025
School of Electronic Engineering, Heilongjiang University, Harbin 150080, China.
Over the past few decades, electron beams have been widely used to treat malignant and benign tumors located in the superficial regions of patients. This study utilized an inorganic scintillator (GdOS:Tb)-based radiation detector to test its response characteristics in an electron-beam radiotherapy environment, in order to determine the application potential of this detector in electron-beam therapy. Owing to the extremely high time resolution of this inorganic scintillator detector (ISD), it is even capable of measuring the pulse information of electron beams generated by the accelerator.
View Article and Find Full Text PDFZ Med Phys
July 2025
Department of Radiotherapy and Radiation Oncology, University Hospital Muenster, Albert-Schweitzer-Campus 1, Muenster, 48149, Germany; Department of Radiation Oncology, University Hospital Leipzig, Stephanstraße 9a, Leipzig, 04103, Germany.
Purpose: This study investigates the charged particle fluence response of two reference ionization chambers (PTW T31021 Semiflex 3D and IBA CC04) and two silicon diode detectors (PTW microSilicon and IBA Razor diode) when measuring relative off-axis profiles in medium- to small-sized photon fields. Monte Carlo (MC) simulations are employed to determine the spectral fluence distribution of charged particles at different off-axis positions in water and within the investigated detectors. The goal is to enhance our understanding of the challenges associated with the dosimetry under non-equilibrium conditions and to calculate off-axis correction factors for the detectors under investigation.
View Article and Find Full Text PDFAdv Sci (Weinh)
July 2025
Beijing Engineering Research Center of Mixed Reality and Advanced Display, School of Optics and Photonics, Beijing Institute of Technology, Beijing, 100081, China.
Augmented reality (AR) presents virtual information seamlessly integrated with real-world scenes, advancing information interaction for human society. Traditional AR displays struggle to simultaneously achieve large depth-of-field (DOF), large viewing eyebox, and wide field-of-view (FOV), which limits their practical applicability. Here, a novel AR near-eye display scheme is proposed that addresses these limitations, providing a large DOF, expansive eyebox, and wide FOV.
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