3 year phd position at TU Wien, Vienna, Austria

The research group at TU Wien (http://atto.photonik.tuwien.ac.at/) has recently demonstrated a new technique for compressing and red-shifting energetic laser pulses.
In this technique laser pulses from an Yb amplifier are propagated in a long gas-filled hollow core fiber to obtain energetic 20fs-pulses with several mJ of energy, spectrally redshifted to a bandwidth of 1200nm-1300nm. Extension of the bandwidth to ~1500nm seems possible.

These energetic, short and frequency-tunable laser pulses will be applied for the following two main research projects, for which Ph.D. positions and Master thesis are currently available:

Project #1: direct driving of High Harmonic Generation (HHG) in the water window

HHG is a consolidated technique which has proven to be very valuable for time-resolved investigations in atoms and molecules in the extreme ultraviolet and soft X-ray spectral region. The main issues are the limit in photon flux and the maximum photon energy (cut-off) which can be reached. The cut-off can be extended by driving HHG with longer wavelengths (thus scaling as λ²), but at the cost of the overall efficiency (which drastically drops as λ-5 - λ-6). Also, the energy losses for the frequency conversion must be taken into account (so far, this was achieved by OPA with typical efficiencies of ~10%). The energy-efficient generation of short mid-IR pulses offers the possibility to generate harmonics with extended cut-off and unprecedented photon flux. The project is focused on laser and X-ray source development, and later on time-resolved investigations of ultrafast dynamics in atoms and molecules by means of soft X-ray – IR pump-probe experiments by monitoring absorption spectra and scattering patterns.

Project #2: generation of Long Wavelength Infrared pulses via DFG

Applying difference frequency generation (DGF) techniques to the original pulses and their redshift replica in non-linear crystals, it will be possible to generate energetic, few-cycle, CEP stable pulses in the long wave IR spectral region with an overall much higher efficiency as compared to multi-stage OPA. Such pulses shall then be used for proof of principle applications, i.e. wavelength scaling of incoherent hard X-rays and for electron wave-packet holography. The project is focused on laser and IR source development, and its applications to proof of principle experiments.

Both projects are experimental.

[1]          Extreme Raman red shift: ultrafast multimode nonlinear space-time dynamics, pulse compression, and broadly tunable frequency conversion, https://doi.org/10.1364/OPTICA.397685 

Job requirements:

·         Master degree in physics or electrical engineering (or an equivalent degree) with high marks

·         Background and interest in optics and photonics

·         Strong attitude towards experimental research

·         Ability to work in a team

·         Problem solving skills

·         Fluent in written and spoken English

We offer:

·         Competitive salary (std. Austrian Ph.D. salary ~1600€ net x 14 times a year)

·         Continuing personal and professional education

·         Central location with very good accessibility in a city regularly ranked first worldwide for life quality

 

For further information about the scientific background, the projects, the Ph.D. program, the application and the employment conditions, please contact us:

Dr. Paolo A. Carpeggiani (paolo.carpeggiani@tuwien.ac.at)