Ultrashort infrared light pulses are the key to a wide range of technological applications. The oscillating infrared light field can excite molecules in a sample to vibrate at specific frequencies, or drive ultrafast electric currents in semiconductors. Physicists from the attoworld team at the Ludwig-Maximilians-Universität München (LMU), the Max Planck Institute of Quantum Optics (MPQ) and the Hungarian Center for Molecular Fingerprinting (CMF) have now succeeded in generating ultrashort mid-infrared pulses and precisely controlling their electric-field waveforms. The basis for the new mid-infrared source is a stabilized laser system that generates light pulses with a precisely defined waveform at near-infrared wavelengths. The pulses consist of only one oscillation of the light wave and are thus only a few femtoseconds long (a femtosecond being one millionth of a billionth of a second, 10-15 s). The team utilizes frequency-mixing processes in nonlinear crystals to translate the near-infrared pulses into controllable infrared waveforms. With this infrared waveform manipulator at hand, new possibilities of optical control for biomedical applications and quantum electronics come into reach.
Picture: Dennis Luck, Alexander Gelin
