Techniques and Equipment
Techniques
In our laboratories at ETHZ we employ a variety of ultrafast pump-probe methods using frequencies ranging from THz to UV. Our group has special expertise in generating high intensity THz pulses as well as narrow-band, intense mid-IR light. These are often used in combination with weaker THz or visible light probes that can investigate the time evolution of the electronic, atomic or magnetic structure via nonlinear and linear optical interactions. We also routinely use FTIR spectroscopy as well as THz-time domain spectroscopy to characterize our materials.
Equipment
Our group uses a large array of different measuring techniques using light. Our experiments cover a large fraction of the electromagnetic spectrum, spanning from x-rays to Teraherz radiation. In addition to that, most experiments have a potential time resolution in the order of 100 fs.
These high requirement can only be met by state-of-the-art equipment. The majority of our experiments were simply impossible to carry out 10 or 15 years ago. We carry out most of our research using both lab-based methods at ETH and at x-ray user facilities around the world.
At ETH, we have two laser systems that support several experimental setups:
- high power amplified Ti:Sapphire laser system with 20 W output and 100 fs pulse length, in conjunction with high power OPAs for wavelenght conversion,
- high repetition rate Ti:Sapphire laser system at 250 kHz and 40 fs pulse length.
The experimental setups are flexible and undergo ongoing development:
- high field THz spectroscopy, 2D spectroscopy and cryogenic sample environment possible,
- 2D spectrometer, operating at different geometries and selected frequencies (THz, IR, VIS),
- pump-probe setups with sum and difference frequency generation,
- time-resolved magneto-optical Kerr effect with external magnet,
- commercial far-infrared FTIR spectrometer.
We also have regular access to synchrotrons and free electron lasers for experiment with x-ray techniques. The group is a world leader in developing new techniques of time-resolved x-ray diffraction and spectroscopy for the study of solid state dynamics.