Nanosecond Broadband Spectroscopy for Laser-Driven Compression Experiments

Dylan Spaulding, University of California, Berkeley


Observation of the optical properties of shock and ramp-compressed samples is a critical capability for high-energy density materials science. In particular, characterization of optical reflectivity can serve as a means to probe the electronic structure in condensed matter. Many laser-driven HED experiments, including some of those planned for the National Ignition Facility, rely on a thorough understanding of the dynamic response of transparent crystalline materials which serve as either the primary sample or as a tamping window through which other measurements are made. Observation of the wavelength-dependent optical properties of materials over a wide spectral band and on nanosecond timescales is thus a potentially powerful tool for a number of HED applications and dynamic compression experiments. Here, we describe a technique for white-light reflectivity measurements using non-linear pumping of an optical fiber,allowing spectrally and temporally resolved observation of the optical properties of the sample at wavelengths between 532-800 nm over timescales of ~3-5nsec.

Abstract Author(s): Dylan Spaulding