Space‐Time Wave Packets from Smith‐Purcell Radiation

Tan, Yi Ji; Pitchappa, Prakash; Wang, Nan; Singh, Ranjan; Wong, Liang Jie

doi:10.1002/advs.202100925

Cited by 13 publications

(7 citation statements)

References 133 publications

(182 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Within this general enterprise, ST wave packets have been recently investigated along exciting new lines of inquiry that we survey here. For example, several technical advances have been reported, including the synthesis of ST wave packets at large bandwidths [243], and at extreme wavelengths in the mid-infrared [244], terahertz, or X-ray regimes [347]. On the conceptual side, several new investigations have enriched our understanding of the structure and behavior of ST wave packets.…”

Section: State-of-the-art Of St Wave Packetsmentioning

confidence: 99%

Space-time wave packets

Yessenov¹,

Hall²,

Schepler³

et al. 2022

Preprint

View full text Add to dashboard Cite

Space-time' (ST) wave packets constitute a broad class of pulsed optical fields that are rigidly transported in linear media without diffraction or dispersion, and are therefore propagation-invariant in absence of optical nonlinearities or waveguiding structures. Such wave packets exhibit unique characteristics, such as controllable group velocities in free space and exotic refractive phenomena. At the root of of these behaviors is a fundamental feature underpinning ST wave packets: their spectra are not separable with respect to the spatial and temporal degrees of freedom. Indeed, the spatio-temporal structure is endowed with non-differentiable angular dispersion, in which each spatial frequency is associated with a single prescribed wavelength. Furthermore, deviation from this particular spatio-temporal structure yields novel behaviors that depart from propagation invariance in a precise manner, such as acceleration with an arbitrary axial distribution of the group velocity, tunable dispersion profiles, and Talbot effects in space-time. Although the basic concept of ST wave packets has been known since the 1980's, only very recently has rapid experimental development emerged. These advances are made possible by innovations in spatio-temporal Fourier synthesis, thereby opening a new frontier for structured light at the intersection of beam optics and ultrafast optics. Furthermore, a plethora of novel spatio-temporally structured optical fields (such as flying-focus wave packets, toroidal pulses, and ST optical vortices) are now providing a swathe of surprising characteristics, ranging from tunable group velocities to transverse orbital angular momentum. We review the historical development of ST wave packets, describe the new experimental approach for their efficient synthesis, and enumerate the various new results and potential applications for ST wave packets and other spatio-temporally structured fields that are rapidly accumulating, before casting an eye on a future roadmap for this field.

show abstract

Section: State-of-the-art Of St Wave Packetsmentioning

confidence: 99%

Space-time wave packets

Yessenov¹,

Hall²,

Schepler³

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…One-dimensional (1D) PhC structures are made of periodically alternating layers. Featuring periods typically of several hundreds of nanometers, 1D PhCs have shown the ability to tailor visible light emission, such as that generated from free electron radiation. − Our use of a 1D model makes our theory valid only for devices whose transverse dimensions are much larger than their thickness, which include many types of large-area detectors . These large-area detectors are widely used in many scintillation fields, including medical X-ray imaging, security scanning, dark matter detection, and neutrino detection. − ,, In this work, the Purcell effect enabled by external PhC cavities allows us to mold the scintillator emission pattern beyond what is possible by just using external structures as reflective/transmissive media.…”

Section: Discussionmentioning

confidence: 99%

Enhancing Large-Area Scintillator Detection with Photonic Crystal Cavities

Bizarri

Birowosuto

et al. 2022

ACS Photonics

Self Cite

View full text Add to dashboard Cite

Scintillators are materials that emit visible photons when bombarded by high-energy particles (X-ray, γ-ray, electrons, neutrinos, etc.) and are crucial for applications, including X-ray imaging and high-energy particle detection. Here, we show that one-dimensional (1D) photonic crystal (PhC) cavities, added externally to scintillator materials, can be used to tailor the intrinsic emission spectrum of scintillators via the Purcell effect. The emission spectral peaks can be shifted, narrowed, or split, improving the overlap between the scintillator emission spectrum and the quantum efficiency (QE) spectrum of the photodetector. As a result, the overall photodetector signal can be enhanced by over 200%. The use of external PhC cavities especially benefits thick and large-area scintillators, which are needed to stop particles with ultrahigh energy, as in large-area neutrino detectors. Our findings should pave the way to greater versatility and efficiency in the design of scintillators for applications, including X-ray imaging and positron emission tomography.

show abstract

“…Those techniques offer an interesting platform to generate x-ray photons with moderately relativistic electrons. [144][145][146][147][148][149] We highlight recent work 21,150 to reveal the similarities and differences between SPR and the previously-mentioned x-ray emission techniques.…”

Section: Smith-purcell Radiationmentioning

confidence: 99%

Free-electron-light interactions in nanophotonics

Roques‐Carmes¹,

Kooi²,

Yang³

et al. 2022

Preprint

View full text Add to dashboard Cite

When impinging on optical structures or passing in their vicinity, free electrons can spontaneously emit electromagnetic radiation, a phenomenon generally known as cathodoluminescence. Free-electron radiation comes in many guises: Cherenkov, transition, and Smith-Purcell radiation, but also electron scintillation, commonly referred to as incoherent cathodoluminescence. While those effects have been at the heart of many fundamental discoveries and technological developments in high-energy physics in the past century, their recent demonstration in photonic and nanophotonic systems has attracted a lot of attention. Those developments arose from predictions that exploit nanophotonics for novel radiation regimes, now becoming accessible thanks to advances in nanofabrication. In general, the proper design of nanophotonic structures can enable shaping, control, and enhancement of free-electron radiation, for any of the above-mentioned effects. Free-electron radiation in nanophotonics opens the way to promising applications, such as widely-tunable integrated light sources from x-ray to THz frequencies, miniaturized particle accelerators, and highly sensitive high-energy particle detectors. Here, we review the emerging field of free-electron radiation in nanophotonics. We first present a general, unified framework to describe free-electron light-matter interaction in arbitrary nanophotonic systems. We then show how this framework sheds light on the physical underpinnings of many methods in the field used to control and enhance free-electron radiation. Namely, the framework points to the central role played by the photonic eigenmodes in controlling the output properties of free-electron radiation (e.g., frequency, directionality, and polarization). We then review experimental techniques to characterize free-electron radiation in scanning and transmission electron microscopes, which have emerged as the central platforms for experimental realization of the phenomena described in this Review. We further discuss various experimental methods to control and extract spectral, angular, and polarization-resolved information on free-electron radiation. We conclude this Review by outlining novel directions for this field, including ultrafast and quantum effects in free-electron radiation, tunable short-wavelength emitters in the ultraviolet and soft x-ray regimes, and free-electron radiation from topological states in photonic crystals.

show abstract

Space‐Time Wave Packets from Smith‐Purcell Radiation

Cited by 13 publications

References 133 publications

Space-time wave packets

Space-time wave packets

Enhancing Large-Area Scintillator Detection with Photonic Crystal Cavities

Free-electron-light interactions in nanophotonics

Contact Info

Product

Resources

About