Undepleted direct laser acceleration.

Intense lasers enable generating high-energy particle beams in university-scale laboratories. With the direct laser acceleration (DLA) method, the leading part of the laser pulse ionizes the target material and forms a positively charged ion plasma channel into which electrons are injected and accelerated. The high energy conversion efficiency of DLA makes it ideal for generating large numbers of photonuclear reactions.

Intense laser interaction with micro-bars.

Intense laser fields interact very differently with micrometric rough surfaces than with flat objects. The interaction features high laser energy absorption and increased emission of MeV electrons, ions, and of hard x-rays. In this work, we irradiated isolated, translationally-symmetric objects in the form of micrometric Au bars.

A full Stokes vector ellipsometry measurement system for in situ diagnostics in dynamic experiments.

A fast ellipsometry system with a resolution of only a few nanoseconds that can simultaneously measure all four Stokes parameters was developed for use in dynamic experiments. Due to its fine temporal resolution, the system is useful for a wide variety of dynamic setups, two of which are presented, fast foil heating and shock compression. As a test case the optical properties of nickel were measured in a fast foil heating setup.

High pressure ellipsometry: a novel method for measuring the optical properties and electronic structure of materials in diamond anvil cells.

High pressure ellipsometry (HPE) method was developed for determining the index of refraction of opaque materials in a diamond anvil cell (DAC). A main difficulty in DAC-based HPE, namely, the pressure-induced birefringence developed in the diamond, was overcome enabling the extraction of the ellipsometric parameters of the sample. The method used was based on the fact that an unpolarized light is unaffected by a retarding optical element and thus reduces the number of unknown parameters in the problem.

Topography retrieval using different solutions of the transport intensity equation.

The topography of a phase plate is recovered from the phase reconstruction by solving the transport intensity equation (TIE). The TIE is solved using two different approaches: (a) the classical solution of solving the Poisson differential equation and (b) an algebraic approach with Zernike functions. In this paper we present and compare the topography reconstruction of a phase plate with these solution methods and justify why one solution is preferable over the other.