Colloquia

Ever since the invention of the laser 50 years ago, scientists have been striving to extend coherent laser-like beams into the x-ray region of the spectrum. Very recently, the prospects for tabletop x-ray beams at wavelengths <10Å have brightened considerably. This advance is the direct result of a new ability to manipulate electrons on their natural, attosecond (10^-18s), time-scales using femtosecond lasers. In recent work we uncovered a new regime of nonlinear optics, where bright laser-like X-ray supercontinua with photon energies >1.6keV (wavelengths < 8Å) can be produced from a tabletop femtosecond laser [1]. This represents the most extreme >5001 order nonlinear optical process known. X-rays are powerful probes of the nanoworld. They penetrate thick samples and can image small objects. This talk will also highlight how ultrafast x-rays can capture the coupled motions of charges, spins, phonons and photons that underlie function on the fastest timescales. [2,3]
1. Popmintchev et al, Science 336, 1287 (2012).
2. Mathias, et al, PNAS 109, 4792 (2012).
3. Rudolf et al., Nature Commun 3, 1037 (2012).