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Attosecond Optoelectronics

Dr. Karpowicz, Attosecond experiments

We study the dynamics of atoms, molecules, and solids on the attosecond time-scale through the observation of controlled electric fields. In order to do this, we investigate new ways of directly measuring infrared, visible, and ultraviolet electric field oscillations through optoelectronic techniques. This allows us to ask and try to answer such questions as: how does an optical wavepacket transform into an electronic wavepacket, and when? And, when does a charge carrier in a solid start acting as one? Answering these questions help us to explore the ultimate limits of optically-controlled electronics.

Using few cycle laser pulses in the middle and near infrared, we can both drive strong-field effects and observe the resulting motion of charge carriers in the field through the radiation they emit. As we have developed a toolbox of time-domain, coherent, field detection techniques, we not only see the basics such as the direction and color of an emitted photon, but have real time-domain access to the oscillating field that emerges from the interaction. We can then trace this back directly to the motion of charges!

To get this to work, we develop:

  • highly-stable, few-cycle (or even sub-cycle) laser pulses
  • coherent detection techniques with unprecedented bandwidth (or time resolution) and sensitivity
  • full-electric-field imaging techniques
  • attosecond metrology in new parameter regimes

Contribution to IMPRS curriculum

Photonics II: ultrafast-laser-pulse generation and ultrafast solid-state optics
Lecturer: Nicholas Karpowicz, Martin Schultze (3+1 hours/week)
Generation and measurement of intense, ultrashort laser pulses. Nonlinear light-matter interactions at high intensities: generation of coherent soft X-rays and attosecond X-ray pulses. High-speed "photography" in the microcosm: capturing the motion of electrons and atoms with femto- and attosecond pulses. Laser-induced breakdown in dielectrics: micro- and nanomachining with lasers. Interaction of (ultrafast light) with solids and band-structure materials, optical resonances, semiconductor optics