In this paper we discuss some of the important issues pertaining to laser acceleration in vacuum, neutral gases, and plasmas. The limitations of laser vacuum acceleration as they relate to electron slippage, laser diffraction, material damage, and electron aperture effects, are discussed. An inverse Cherenkov laser acceleration configuration is presented in which a laser beam is self-guided in ...

In this paper, the laser recording of thin diffraction gratings in deoxyribonucleic acid (DNA) – cetyltrimethyl-ammonium chloride (CTMA) surfactant doped with Rhodamine 610 (Rh610) films is experimentally investigated. The diffraction efficiency of the gratings induced in dye-doped DNA films by the interference of two Ar laser beams at 514.5 nm wavelength is monitored using a He-Ne probe beam (...

Thermal-wave fields have been optically generated and measured, using spatially resolved scanning photopyroelectric detection. Both single laser-beam diffraction profiles and thermal-wave patterns from two laser beams, interfering coherently in a manner analogous to Young's optical-wave experiment, have been produced. The diffraction and interference images have further been shown to be in exce...

Imaging the transient process of molecules has been a basic way to investigate photochemical reactions and dynamics. Based on laser-induced electron diffraction and partial one-dimensional molecular alignment, here we provide two effective methods for reconstructing two-dimensional structure of polyatomic molecules. We demonstrate that electron diffraction images in both scattering angles and b...

Diffraction of multi-level atoms by an evanescent wave reflective diffraction grating is modeled by numerically solving the time-dependent Schrödinger equation. We are able to explain the diffraction observed in experiments with metastable Neon. This is not possible using a two-level atom model. The multi-level model predicts sensitive dependence of diffraction on the laser polarization. For pu...

The point-diffraction interferometer (PDI) is a simple common-path interferometer capable of measuring optical-path differences (OPD) directly. This interferometer, first described by Smartt in 1972,1,2 has since become available commercially for use in the visible spectrum. Currently activity in laser-fusion and high-energy-laser systems has stimulated interest in extending PDI principles to t...

Ultrafast time-resolved electron diffraction based on a photocathode rf electron gun is being developed in Osaka University to reveal the hidden dynamics of intricate molecular and atomic processes in materials. The photocathode rf gun generates a femtosecond-bunch electron beam by femtosecond laser driving. The transverse emittance, bunch length and energy spread were measured. The growths of ...

Time-resolved x-ray diffraction with picosecond temporal resolution is used to observe scattering from impulsively generated coherent acoustic phonons in laser-excited InSb crystals. The observed frequencies and damping rates are in agreement with a model based on dynamical diffraction theory coupled to analytic solutions for the laser-induced strain profile. The results are consistent with a 1...

A particle-sizing method based on laser diffraction suffers from several major pitfalls, namely: (1) the method is based on false assumptions (2) the reported distribution can be skewed towards the smaller range (3) the results vary significantly with optical parameters (4) the software used for calculation of results can not be independently validated (5) the accuracy of measurements for non-s...

We have developed a method for laser beam manipulation by using a colloid of nickel nanorods produced by electroplating chemistry. It is shown that the shape of the laser beam passing through a colloid of nickel nanorods can be altered by varying the applied magnetic field. This effect is caused by multiple scattering and diffraction of the laser beam by the nanorods. Compared with spherical na...