research projects

development of the world’s first terawatt-scale light waveform synthesizer

Fig. 1. Mohammed Hassan aligning the lightwave synthesizer.

We develop what will be the world’s first light source delivering pulses shorter than their wave cycle, with controlled waveform and terawatt-scale peak powers. The resultant next-generation ultrafast technology will constitute a major pillar of both LAP’s future laser infrastructure as well as that of the new research center in photonics at KSU. The project will provide, for the first time in the history of science, light supercontinua spanning containing frequencies all the way from the ultraviolet to the infrared. The coherent superposition of these frequencies will permit, again, for the first time, synthesis of a vast variety of intense light waveforms, with their ultra-strong electric field being tailored on a sub-femtosecond or attosecond timescale.

Contact: Eleftherios Goulielmakis
  full address

towards a brilliant extreme ultraviolet and soft-x-ray light source

Fig. 2. Ioachim Pupeza optimizing the enhancement cavity.

We aim at developing a light source producing femtosecond laser pulses at multi-10-kilowatt power levels inside a passive (enhancement) cavity. Laser-driven high harmonic generation (HHG) is a well-established technique for the production of coherent (laser-like) radiation in the extreme ultraviolet (XUV) and soft-X-ray (SXR) spectral range. Due to the high intensities required, these sources typically rely upon complex chirped-pulse-amplification systems operated up to pulse repetition rates of a few kHz, which limits their application potential. This project aims at extending this capability in developing a brilliant, coherent source of ultrashort-pulsed XUV and SXR pulses at MHz repetition rates. This new source will open up unprecedented applications including highly temporal and spatially resolved spectroscopy on water-solvated proteins, time-resolved coincidence studies, biomedical imaging, nanoplasmonics as well as XUV holography and lithography.

Contact: Ioachim Pupeza
  full address

ultrahigh-power, waveform-controlled Yb:YAG laser oscillator

Fig. 3. Oleg Pronin with the high power Yb:YAG laser oscillator.

Waveform-controlled (carrier-envelope-phase (CEP)-stabilized) few-cycle laser pulses have so far been exclusively generated from Kerr-lens-mode-locked (KLM) Ti:sapphire oscillators with pulse energies of several nanojoules. At LMU, we have recently demonstrated the world’s first femtosecond Yb:YAG thin-disk oscillator and shortly thereafter its CEP-stabilization. In its world premiere, CEP stabilization was implemented via modulating the intracavity power with an acousto-optic modulator driven by the f-2f beat signal. In this project, we implement the CEP stabilization via modulating the pump power with the same signal, offering a more compact, user-friendly system. The oscillator will form the basis for high-power few-femtosecond laser systems developed within the collaboration. The project is supported through the International Twinning Program of KSU.

Contact: Oleg Pronin Alexander Apolonskiy
  full address full address

development of a kilowatt Yb:YAG regenerative amplifier

Fig. 4. Picture of a prototype disc amplifier.

Picosecond-laser-driven broadband optical parametric amplification (OPA) of few-cycle laser pulses to millijoule energies and the potential scalability of the technique to much higher energies has opened the prospect of a new (third) generation of femtosecond technology holding promise of surpassing the average power of current sources by orders of magnitude. The key to exploiting this potential are high-power picosecond Yb:YAG thin-disk amplifiers scalable towards the kilowatt average power frontier. It is one central aim of this project to exploit this potential and demonstrate the first kilowatt-scale picosecond source by drawing on Yb:YAG thin-disk laser technology. The project is supported through the International Twinning Program of KSU.

Contact: Helena Barros
  full address

multi-terawatt source of waveform-controlled few-cycle light

Fig. 5. Light Wave Synthesizer (LWS) – 1 (LWS-1) produces millijoule near-single-cycle (near-10-fs) waveform-controlled MIR pulses.

The octave-spanning (700-1400nm) pulses from the KLM Yb:YAG disk oscillator will be amplified in a broadband optical parametric amplifier (OPA) chain. For pumping this chain, the Yb:YAG amplifier developed within the collaboration will be frequency doubled in a second harmonic generation (SHG) stage. Femtosecond synchronization of the broadband signal and narrow-band pump pulses for the OPA will be provided by an optical synchronization system demonstrated recently. Following amplification in nonlinear crystals the chirped broadband near-infrared pulses are compressed to their Fourier-limit (about 4 fs) with a set of chirped multilayer dispersive mirrors developed also in the framework of the project. The project is supported through the International Twinning Program of KSU.

Contact: Helena Barros
  full address

attosecond electronic population dynamics

Fig. 6. View into the attosecond experimental chamber.

Electronic population transfer in solid materials as semiconductors and dielectrics constitutes the core of modern silicon based technology and is thus the cornerstone of machine intelligence, communication technology, data acquisition, processing and exchange. The technological advances achieved in solid state physics in the past 100 years have promoted all other branches of science to a new level and continue pushing their progress. These developments culminated in electronic circuits operating at gigahertz rates whilst the uncertainty principle applied to typical semiconductor band-gap energies holds promise for the ultimate speed of electronic response beyond optical frequencies (Petahertz) corresponding to attosecond response times. Bridging this gap that spans 6 orders of magnitude and speeding up electronics accordingly requires the development of tools to track and control these electronic phenomena on their genuine timescale that will yield a basis for a detailed understanding of the dynamic processes of electronic population inside solids. The project aims on applying the tools of attosecond metrology developed in the past years to electronic processes inside solids thus opening a completely new field of science. The project is supported through funding by the National Plan for Sciences and Technology (NPST).

Contact: Elisabeth Bothschafter Zeyad Alahmed
  full address full address

towards ultrafast lightwave electronics

Fig. 7. View of the setup use to control currents in nanodevices.

The project consists of exploiting ultrafast photonics tools for demonstrating electronic control in circuits patterned via state-of-the-art nanofabrication techniques. We rely on intense phase-stable near single-cycle optical pulses to inject charge carriers and control their trajectories in nanoscaled metal/dielectric and metal/semiconductor interfaces. The proof-of-principle experiment will not only enable direct time-domain access to fundamental processes which dictate charge transport in condensed matter, but also open pathways towards solid-state nanoelectronics and ultrafast logic operations performing at lightwave frequencies. This research project combines the unique optical tools available at MPQ with the state-of-the-art nanofabrication facilities of KAIN. Such collaboration will bridge the gap between high-end nanotechnology and ultrafast photonics. Its success could therefore potentiate groundbreaking ultrafast nanoelectronics applications in the framework of the National Nanotechnology program. The project is supported through funding by the National Plan for Sciences and Technology (NPST).

Contact: Nicholas Karpowicz Abdallah Azzeer
  full address full address

towards ultrafast plasmonic metal-semiconductor hybrid devices

Fig. 8. Nanostructred materials prepared by the Kleineberg group.

Ultrafast information processing in nanoscaled electronic devices with ever increasing degree of miniaturization (“Moores law”) is today considered to be key technology of a high-tech civilization. However, for current CMOS electronics physical principles do set limits not only for the degree of nanoscale integration (due to material properties and quantum size effects to ~ 10 nm) but also for the available processing bandwidth (“speed”) which is limited to microwave frequencies (~Ghz). Optical information processing could extend this bandwidth limit into the PHz regime, however the degree of chip integration is limited by the wavelength of light to typically 0.5 micron. Nanoscaled devices (10 nm) with large bandwidth (100 THz and above) require research on new physical concepts which adapt processing with optical light wave fields at spatial scales below the diffraction limit. Surface Plasmons as bound electromagnetic waves due to collective free electron oscillations provide a very promising route towards this goal. We aim for ultrafast and active control of surface plasmons in metal-semiconductor hybrid devices and nanoswitches, where the enhanced nanolocalized surface plasmon field at the interface of a metal-dielectric or metal-semiconductor hybrid nanostructure coherently controls the non-linear optical response of an adjacent semiconductor (or dielectric) nanostructure on a fs time scale. Our research paves the way towards the development of ultrafast plasmonic switches or ultimately towards plasmonic transistors with unprecedented bandwidth of up to 100 Thz, three orders of magnitude larger than today’s microwave electronics.

Contact: Ulf Kleineberg
  full address

control of hydrogen migration in hydrocarbons

Fig. 10. Ali Alnaser at the attosecond beamline AS-5.

The rearrangement of hydrogen bonds is one of the most important dynamic reactions in the chemistry related to biology, combustion and catalysis, motivating considerable efforts to monitor and ultimately control it. Previous work indicated that the prototypical proton transfer in hydrocarbons occurs on a sub-10 femtosecond timescale, making its real-time observation and control extraordinarily difficult. As an additional challenge, conventional control schemes do not provide means for a directional manipulation of hydrogen migration in symmetric hydrocarbons. In this project we aim to steer hydrogen rearrangement in hydrocarbons using the electric field of few-cycle laser light shaped on a sub-cycle, i.e. sub-femtosecond, time scale. Controlling the directionality of the motion of nuclei in chemical reactions opens the path towards steering chemical reactions with the light field as a new photonic reagent.

Contact: Matthias Kling
  full address

breath-analysis for the diagnosis of diseases

Fig. 11. Enhancement cavity for new applications including breath-analysis.

Absorption laser spectroscopy is a powerful technique for qualitative and quantitative analysis of trace concentrations of atoms and molecules. As such it can find application in the medical multi trace detection of molecules in the air exhaled by patients. Compared to current clinical devices based on mass spectrometry, this optical technique has the potential of being broader applicable and orders of magnitude more sensitive. It will enable identifying early stages of not only respiratory diseases and chronic health conditions, but also detecting the presence of carcinogens, diabetes and other pathological conditions. We have developed frequency comb laser spectroscopy and a novel optical multi-pass cell based on highly reflecting confocal mirrors, achieving both long optical paths and uniform coverage of the interaction volume to obtain high sensitivity and high selectivity.

Contact: Alexander Apolonskiy
  full address