Smith-Purcell radiation from time grating
Abstract
Smith-Purcell radiation (SPR) occurs when an electron skims above a spatial grating, but the fixed momentum compensation from the static grating imposes limitations on the emission wavelength. It has been discovered that a temporally periodic system can provide energy compensation to generate light emissions in free space. Here, we introduce temporal SPR (t-SPR) emerging from a time grating and propose a generalized t-SPR dispersion equation to predict the relationship between radiation frequency, direction, electron velocity, modulation period, and harmonic orders. Compared to conventional SPR, t-SPR can: 1) Provide a versatile platform for manipulating SPR emission through temporal modulation (e.g., period, amplitude, wave shape). 2) Exhibit strong robustness to the electron-grating separation, alleviating the constraints associated with extreme electron near-field excitation. 3) Introduce additional energy channels through temporal modulation, enhancing and amplifying emission.
Cite
@article{arxiv.2311.07381,
title = {Smith-Purcell radiation from time grating},
author = {Juan-Feng Zhu and Ayan Nussupbekov and Wenjie Zhou and Zicheng Song and Xuchen Wang and Zi-Wen Zhang and Chao-Hai Du and Ping Bai and Ching Eng Png and Cheng-Wei Qiu and Lin Wu},
journal= {arXiv preprint arXiv:2311.07381},
year = {2023}
}
Comments
6 pages, 3 figures