Streak camera

Abstract: An electron generated by x-ray photoionization can be deflected by a strong laser field Its energy and angular distribution depends on the phase of the laser field at the time of ionization This phase dependence can be used to measure the duration and chirp of single sub100-attosecond x-ray pulses

Abstract: A high-temperature plasma is created when an intense laser pulse is focused onto the surface of a solid. An ultrafast pulse of x-ray radiation is emitted from such a plasma when the laser pulse length is less than a picosecond. A high-speed streak camera detector was used to determine the duration of these x-ray pulses, and computer simulations of the plasmas agree with the experimental results. Scaling laws predict that brighter and more efficient x-ray sources will be obtained by the use of more intense laser pulses. These sources can be used for time-resolved x-ray scattering studies and for the development of x-ray lasers.

Abstract: A few-femtosecond X-ray streak camera has been realized using a pump–probe scheme that samples the transient response of matter to ionizing soft X-ray radiation in the presence of an intense synchronized terahertz field. Borrowing its concept from attosecond metrology, the femtosecond X-ray streak camera fills the gap between conventional streak cameras with typical resolutions of hundreds of femtoseconds and streaking techniques operating in the sub-femtosecond regime. Its single-shot capability permits the duration and time structure of individual X-ray pulses to be determined. For several classes of experiments in time-resolved spectroscopy, diffraction or imaging envisaged with novel accelerator- and laser-based short-pulse X-ray sources this knowledge is essential, but represents a major challenge to X-ray metrology. Here we report on the single-shot characterization of soft X-ray pulses from the free-electron laser facility FLASH. A streak camera for characterizing the ultrashort X-ray pulses produced by a free-electron laser is reported. The scheme has a single-shot capability, a resolution of a few femtoseconds and is expected to become a useful tool for X-ray metrology, including experiments involving time-resolved spectroscopy and imaging.

Abstract: We describe temporal and spectroscopic measurements of high-density plasmas produced by focusing intense, 160-fsec laser pulses on solids. Soft x-ray emission with a duration of 2 +- 2 psec is observed up to photon energies of a kilovolt. We observe reduced emission from long-lived spectral lines, indicating the presence of a short-lived, high-density plasma. Reflectivity measurements indicate that absorption of the laser pulse occurs at the surface of the solid before it expands.

Abstract: The generation of intense ultrashort light pulses in mode-locked laser systems has made possible a wide range of new experiments designed to study the interaction of light with matter. For the quantitative interpretation of the results, accurate measurement of the optical pulse structure is essential, and it is the purpose of this paper to review all the diagnostic techniques currently available. The recent rapid development of the electron-optical streak camera is highlighted, while considerable space is devoted to an extensive description of the many second- and higher order correlation measurements (including the popular two-photon fluorescence method). A discussion of ultrafast shutter techniques is also included, together with a section on pulse chirping and dynamic spectroscopy.