Generation of Attosecond Light Pulses from Gas and Solid State Media

Abstract

Real-time observation of ultrafast dynamics in the microcosm is a fundamental approach for understanding the internal evolution of physical, chemical and biological systems. Tools for tracing such dynamics are flashes of light with duration comparable to or shorter than the characteristic evolution times of the system under investigation. While femtosecond (fs) pulses are successfully used to investigate vibrational dynamics in molecular systems, real time observation of electron motion in all states of matter requires temporal resolution in the attosecond (1 attosecond (asec) = 10 −18 s) time scale. During the last decades, continuous efforts in ultra-short pulse engineering led to the development of table-top sources which can produce asec pulses. These pulses have been synthesized by using broadband coherent radiation in the extreme ultraviolet (XUV) spectral region generated by the interaction of matter with intense fs pulses. Here, we will review asec pulses generated by the interaction of gas phase media and solid surfaces with intense fs IR laser fields. After a brief overview of the fundamental process underlying the XUV emission form these media, we will review the current technology, specifications and the ongoing developments of such asec sources.

Characterisation and Modelling of Ultrashort Laser-Driven Electromagnetic Pulses

“…from few hundreds of MHz up to THz 1 , electromagnetic pulses (EMP's) through different regimes of interactions [2][3][4][5][6] . When high intense laser target interaction takes place [7][8][9] , a significant portion of electrons escape the target and a fraction of those electrons are accelerated towards relativistic energies generating an ultrashort burst of electromagnetic pulse (EMP) as given by the Lienard Wiechert potentials [10][11][12][13][14][15] . Moreover, the remaining positive charge 16 on the target drives a re-circulating current in the vicinity of the laser spot that gives rise to a THz radiation.…”

Theory of relativistic radiation reflection from plasmas

“…Such Relativistic intensities can be achieved with high-intensity optical laser pulses, while overdense plasma with various scales of density transition at the interface is naturally formed by the ionization, heating and thermal expansion of solids exposed to pre-pulse light. The prospects of using laser-solid interactions for various applications, ranging from high-harmonic generation to plasma heating, has stimulated theoretical and experimental studies of the non-linear reflection process [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] .…”

Tabletop nonlinear optics in the 100-eV spectral region

“…Moreover, we determine the two-photon ionization cross sections for this process. This progress is allowed by a 100-fold increase in the XUV pulse energy, utilizing the quadratic scaling of the harmonic yield with the diameter of the interaction region [32][33][34]. A novel scheme for broadband amplification of sub-two-cycle laser pulses towards multi-terawatt (multi-TW) peak power allows us to maintain the driving laser intensity at the required level in a much larger focus.…”