The rotational Doppler effect has attracted extensive attention, caused by the angular momentum and energy exchange between rotating objects and waves. However, most previous works used a simple rotation frame, which made use of only a single-round angular momentum and energy exchange. We propose and demonstrate a frame containing a spiral phase plate cascaded with rotating targets to make an amplification of the traditional Doppler shift, and reduce the diffusion of orbital angular momentum modes by half, which means the distance of practical application is doubled theoretically. To this end, an experiment is carried out to verify the frame. It shows a more practical, convenient, and non-destructive method to measure the rotational speed of a remote target.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/AO.438997 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Plantar sensation associates with gait instability in older adults.
J Neuroeng Rehabil
January 2025
Department of Mechanical & Aerospace Engineering, University of Florida, Gainesville, FL, USA.
Background: Advanced age brings a loss of plantar sensation, represented, for example, as higher sensation thresholds in standardized testing. This is thought to contribute to an increased risk of falls among older adults - an intuitive premise that has yet to be fully investigated, especially in the context of walking balance. The purpose of this study was to quantify the association between plantar sensation and the instability elicited by a suite of walking balance perturbations that differ in direction and context in a cohort of n = 28 older adults (73.
View Article and Find Full Text PDFPatients with multiple sclerosis and low disability display cautious rotational behavior during gait initiation.
Clin Biomech (Bristol)
January 2025
Univ. Polytechnique Hauts-de-France, LAMIH, CNRS, UMR 8201, F-59313 Valenciennes, France.
Background: Multiple sclerosis induces locomotor impairments. The objective was to characterize the effects of Multiple Sclerosis on whole-body angular momentum control during gait initiation.
Methods: Fifteen patients with Multiple Sclerosis with Expanded Disability status scale of 2.
Thomas precession, relativistic torque, and non-planar orbits.
Eur Phys J C Part Fields
January 2025
Department of Physics, University of Alberta, Edmonton, AB T6G 2E1 Canada.
We analyze the angular momentum balance for a particle undergoing Thomas precession. The relationships among relativistic torque, the center of mass, and the center of inertia for a spinning particle are clarified. We show that spin precession is accompanied by orbital angular momentum precession, and present examples of the resulting out-of-plane motion.
View Article and Find Full Text PDFMeasuring high-efficiency perfect composite vortex beams with reflective metasurfaces in microwave band.
Nanophotonics
January 2025
Departments of Optics and General Physics, Francisk Skorina Gomel State University, Sovetskaya Str. 104, Gomel 246019, Belarus.
Optical vortex beams carrying orbit angular momentum have attracted significant attention recently. Perfect vortex beams, characterized by their topological charge-independent intensity profile, have important applications in enhancing communication capacity and optimizing particle manipulation. In this paper, metal-insulator-metal copper-coin type reflective metasurfaces are proposed to generate perfect composite vortex beams in X-band.
View Article and Find Full Text PDFHybrid entanglement carrying orbital angular momentum.
Sci Bull (Beijing)
January 2025
State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006, China; Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China. Electronic address:
Hybrid continuous-variable (CV) and discrete-variable (DV) entanglement is an essential quantum resource of hybrid quantum information processing, which enables one to overcome the intrinsic limitations of CV and DV quantum protocols. Besides CV and DV quantum variables, introducing more degrees of freedom provides a feasible approach to increase the information carried by the entangled state. Among all the degrees of freedom of photons, orbital angular momentum (OAM) has potential applications in enhancing the communication capacity of quantum communication and precision of quantum measurement.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!