Ultr-intense and Ultra-fast laser-matter interaction physics

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The main target of this mostly-experimental research program is the set of new physical relations implicit in  the interplay between matter and ultrashort ultra-intense optical fields of femtosecond pulses.  The principal near-term efforts will be concentrated in two areas:  1) fairly basic plasma physics which arises at ultra-high, relativisitically relevant intensities (> 10^{18} W  cm^{-2}):  high-harmonic generation, attosecond pulse generation, changes in Debye shielding under  high-field interactions, relativistic changes in laser-particle coupling, and generation of energetic ions and  electrons; and  2) fairly applied optical- and plasma-physics relevant to ultrafast-laser materials-processing of glasses and  metals, including micromachining and direct index-writing;  we are also studying related problems with  biotissues, relevant to medical applications.The first of these areas is likely to contribute to basic understanding of relativistic laser-plasma interactions,  and may lead to practical applied physics relevant to the 'fast ignitor' scheme of laser-fusion.  Training and  preliminary experiments can take place on the terawatt CPA laser in my laboratory, but most publishable work  must take place on one of the large international laser systems, e.g., CEA-Saclay ('Salle Chaude') in France, or  the ALLS laser system in Canada.The second area is experimentally related, in that it involves ultrafast lasers but at more moderate intensities.   This meets the needs for hands-on training of students in laser-matter interaction experiments, and provides an  applied and industrially relevant component of research while still emphasizing the science. This work uses  two systems in my own laboratories:  a 133 MHz pulsetrain burst laser system of 1 ps pulses, and a system of  100fs pulses at kHz and 80 MHz rates. The research includes a modest analytical and computational theory component, in-house and in collaboration  elsewhere, including particle-in-cell (PIC) code simulations of relativistic laser-plasma interactions in 1D and  in 2D, and also molecular dynamic (MD) modelling of solids.  Analytically, we conduct effective-dielectric  modelling of nanostructured materials, and of beam-channelling in plasmas.The thorniest problem of intense laser-plasma interaction physics has been to observe new effects while at the  same time one determines the conditions of interaction empirically -- a particularly difficult and complex  diagnostic problem for ultra-intense laser-produced plasmas.  My research style has been to set cleanly  defined/diagnosed experimental problems, suited for comparison to theoretical predictions, rather than  immediately to pursue 'extreme' conditions phenomenologically.  The expertise we have developed in  diagnostics and also in modelling are well-suited to a group the size of mine.