相关论文: A Method to Determine the Ultrafast Laser Beams Sp…
Flash radiography of large hydrodynamic experiments driven by high explosives is a diagnostic method in use at many laboratories. A major contributor to the practical resolution obtained by this point-projection technique is the size of the…
Ultralow emittance ($\leq20$ nm, normalized) electron beams with $10^5$ electrons per bunch are obtained by tightly focusing an ultrafast ($\sim$ 100 fs) laser pulse on the cathode of a 1.6 cell radiofrequency photoinjector. Taking…
A study of Helium-Neon laser plasma lines was done using a double grating spectrometer and a He-Ne laser with an emission wavelength of 632.8 nm (15,802 cm$^{-1}$). The absolute wavenumber, measured to within $\sim0.1$ cm$^{-1}$, and…
Novel schemes for generating ultra-low emittance electron beams have been developed in the last years and promise compact particle sources with excellent beam quality suitable for future high-energy physics experiments and free-electron…
We extend the Bayesian model fitting shape measurement method presented in Miller et al. (2007) and use the method to estimate the shear from the Shear TEsting Programme simulations (STEP). The method uses a fast model fitting algorithm…
Structured light harnessing multiple degrees of freedom has become a powerful approach to use complex states of light in fundamental studies and applications. Here, we investigate the light field of an ultrafast laser beam with a…
The pepper-pot method is a widely used technique, originally proposed for measuring the emittance of space-charge-dominated electron beams from radio-frequency photoinjectors. With recent advances in producing high-brightness electron beams…
The paper aims at presenting a didactic and self-contained overview of Gauss-Hermite and Gauss-Laguerre laser beam modes. The usual textbook approach for deriving these modes is to solve the Helmoltz electromagnetic wave equation within the…
Rapid development of ultrafast ultraintense laser technologies continues to create opportunities for studying strong-field physics under extreme conditions. However, accurate determination of the spatial and temporal characteristics of a…
A logarithm processing algorithm to measure beam transverse size and position is proposed and preliminary experimental results in Hefei Light Source II (HLS II) are given. The algorithm is based on only 4 successive channels of 16 anode…
We study the inverse problem of localization (imaging) of a laser beam from measurements of the intensity of light scattered off-axis by a Poisson cloud of small particles. Starting from the wave equation, we analyze the microscopic…
The lasing behavior of one dimensional GaAs nanobeam cavities with embedded InAs quantum dots is studied at room temperature. Lasing is observed throughout the quantum dot PL spectrum, and the wavelength dependence of the threshold is…
This letter proposes a new method based on ultrafast high energy electron radiography to diagnose transient electromagnetic field. For the traditional methods, large scattering from matter will increase the uncertainty of measurement, but…
In the experiment of flash-radiography, the quality of acquired image strongly depends on the focal size of the x-ray source spot. A variety of techniques based on imaging of pinhole, slit and rollbar are adopted to measure the focal spot…
Beam quality is a fundamental aspect for evaluating the performance of laser sources. $M^2$-measurements serve as the gold standard for beam quality assessment since the 1990s. The measured $M^2$-parameter indicates similarity to the pure…
Beam displacement measurements are widely used in optical sensing and communications; however, their performance is affected by numerous intrinsic and extrinsic factors including beam profile, propagation loss, and receiver architecture.…
Wavefront errors are a common artifact in laser light generation and imaging. They can be described as an aberration from the spherical wavefront of an ideal Gaussian beam by combinations of higher-order Hermite- or Laguerre-Gaussian terms.…
Precision measurement of small separations between two atoms or molecules has been of interest since the early days of science. Here, we discuss a scheme which yields spatial information on a system of two identical atoms placed in a…
Laser-electron beam collisions that aim to generate electron-positron pairs require laser intensities $I \gtrsim 10^{21} ~\textrm{W/cm}^2$, which can be obtained by focusing a 1-PW optical laser to a spot smaller than 10 $~\mu$m. Spatial…
When an ultrashort laser pulse is tightly focused to a size approaching its central wavelength, the properties of the focused spot diverge from the diffraction limited case. Here we report on this change in behavior of a tightly focused…