Extreme ultraviolet interferometry of warm dense matter in laser plasmas

L. M. R. Gartside, G. J. Tallents, A. K. Rossall, E. Wagenaars, D. S. Whittaker, M. Kozlova, J. Nejdl, M. Sawicka, J. Polan, M. Kalal, B. Rus

Research output: Contribution to journalArticlepeer-review


We demonstrate that interferometric probing with extreme ultraviolet (EUV) laser light enables determination of the degree of ionization of the "warm dense matter" produced between the critical and ablation surfaces of laser plasmas. Interferometry has been utilized to measure both transmission and phase information for an EUV laser beam at the photon energy of 58.5 eV, probing longitudinally through laser-irradiated plastic (parylene-N) targets (thickness 350 nm) irradiated by a 300 ps duration pulse of wavelength 438 nm and peak irradiance 10(12) W cm(-2). The transmission of the EUV probe beam provides a measure of the rate of target ablation, as ablated plasma becomes close to transparent when the photon energy is less than the ionization energy of the predominant ion species. We show that refractive indices eta below the solid parylene N (eta(solid) = 0.946) and expected plasma values are produced in the warm dense plasma created by laser irradiation due to bound-free absorption in C+. (C) 2010 Optical Society of America

Original languageEnglish
Pages (from-to)3820-3822
Number of pages3
JournalOptics Letters
Issue number22
Publication statusPublished - 15 Nov 2010



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