Science at the Timescale of the Electron: Harnessing the Extreme Nonlinear Optics of High Harmonic Generation for Tabletop Coherent X-Rays

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, we used tabletop ultraviolet and mid-infrared femtosecond lasers to achieve this goal, and create bright X-ray beams at wavelengths spanning from the UV to <10Å.[1-3] The X ray waveforms that are generated represent a coherent version of the Rontgen X-ray tube in the soft X-ray region. Moreover, the limits of this new light source are not yet known. Finally, new 3D attosecond metrology capabilities enable us to characterize some of the most complex coherent light fields to date, with amplitude, phase and polarization states that are dynamically changing on timescales much less than an optical cycle. Applications in understanding quantum materials will also be discussed.

1. Science 348, 530 (2015)

2. Science 350,1225 (2015)

3. Science 336, 1287 (2012)

4. Sciences Advances, in press (2016)