Related papers: Application of Volume diffraction grating for Tera…
Evaluating the Kirchhoff-Fresnel diffraction integral is essential in studying wave effects in astrophysical lensing, but is often intractable because of the highly oscillatory integrated. A recent breakthrough was made by exploiting the…
Presented here is the development and demonstration of a tunable cavity-enhanced terahertz frequency-domain optical Hall effect technique. The cavity consists of at least one fixed and one tunable Fabry-P\'erot resonator. The approach is…
Diffraction gratings have been proposed as core optical elements in future laser-interferometric gravitational-wave detectors. In this paper we derive equations for the coupling between alignment noise and phase noise at diffraction…
Using transient grating spectroscopy, we measure thermal diffusivity and surface acoustic wave speed in tungsten exposed to different fluences of deuterium plasma. Scanning electron microscopy (SEM) shows the formation of surface blisters…
This paper presents simulations of the trajectories of high-energy ions through several bent crystal layers. At certain layer alignments volume reflection occurs from each layer and the resultant multiple volume reflection angle is…
Backward terahertz radiation can be produced by a high-intensity laser normally incident upon an underdense plasma. It is found that terahertz radiation is generated by electrons refluxing along the bubble shell. These shell electrons have…
Periodic multilayers are nowadays widely used to perform x-ray analysis in the soft x-ray range (photon energy lower than 1 keV). However, they do not permit to obtain high-resolution spectra like natural or synthetic crystals. Thus,…
In text-to-speech (TTS) and voice conversion (VC), acoustic features, such as mel spectrograms, are typically used as synthesis or conversion targets owing to their compactness and ease of learning. However, because the ultimate goal is to…
A full (2$\pi$) phase modulation is critical for efficient wavefront manipulation. In this article, a metasurface based on graphene long/short-strip resonators is used to implement a dynamic 2$\pi$ phase modulation by applying different…
We present a comprehensive analysis of coherence properties of the radiation from X-ray free electron laser (XFEL). We consider practically important case when XFEL is optimized for maximum gain. Such an optimization allows to reduce…
Resonances in optical systems are useful for many applications, such as frequency comb generation, optical filtering, and biosensing. However, many of these applications are difficult to implement in optical metasurfaces because traditional…
A composite plasmonic slab based on double-layer metallic gratings and a dielectric film is experimentally and numerically demonstrated in terahertz (THz) regions, which can support two resonance modes and then form a broad bandgap (40%).…
We study theoretically a multi-frequency response of electrons in confined graphene subject to dc-ac driven fields. We explore the possibility for using graphene nanoribbons (GNRs) to generate and amplify terahertz (THz) radiations in…
We review the theory of FEL oscillators operating with tapered undulators. We consider the case of a uniform tapering and introduce a parameter which characterizes the effect of the tapering on the gain and on the saturation intensity. We…
One of the important advantages of optical metasurfaces over conventional diffractive optical elements is their capability to efficiently deflect light by large angles. However, metasurfaces are conventionally designed using approaches that…
Recent progress in short wavelength free-electron lasers extending from the extreme ultraviolet through the x-ray regime have opened new avenues for industrial and research applications. A high-gain/low-Q oscillator, i.e., a regenerative…
Modern x-ray free-electron lasers (XFELs) produce x-ray pulses of exceptional transverse coherence. This is due largely to the process of optical guiding by which the radiation is both refractively guided by the bunched electron beam and…
In this work, a reflective beam-splitter based on a metallic Ronchi diffraction grating normally illuminated is designed and analysed. This kind of beam-splitter could have potential applications in photonics and optical technologies in…
Transistor structures comprising graphene and sub-wavelength metal gratings hold a great promise for plasmon-enhanced terahertz detection. Despite considerable theoretical effort, little experimental evidence for terahertz plasmons in such…
We consider a graphene sheet encapsulated in a two-dimensional metallic grating and a substrate ($\mathrm{Al_{2}O_{3}}$) and subjected to an external magnetic field (in Faraday configuration). The grating consists of a thin perfectly…