MBI (Berlin, Germany)

MBI conducts basic research in nonlinear optics, ultrafast dynamics, the interaction of matter with laser light, and into the resulting applications. It develops and utilizes ultrashort and ultrafast lasers and laser-based short-pulse light sources in a wide spectral range in conjunction with nonlinear spectroscopy methods, as well as combining lasers with x-ray pulses from free electron lasers and synchrotrons.
Research highlights

MBI
Max-Born Institute for Nonlinear Optics and
Short Pulse Spectroscopy, Berlin, Germany

MBI

www.mbi-berlin.de

Contact: Daniela Stozno

Laser Development

The highest average output power of 27 W sets a new record for an OPCPA system in the 2 µm wavelength region, and the soft X-ray continuum generated through HHG can extend to around 0.55 keV, thus covering the entire water window. With a repetition rate still enabling pump-probe experiments on condensed matter samples, the system can be used for many applications. [Opt. Express 28, 8724 (2020)]

Quantum Optics

Photoluminescence measurements in ZnO show a very broad emission band in the visible range from 420 to 800 nm, which exhibits three distinct peak-like contributions in the Green, Yellow and Red at around 520, 590 and 720 nm (2.38, 2.10 and 1.72 eV). These bands were found to correspond to emissions most likely associated with oxygen vacancies, Au impurities and Zn interstitials, and the emission intensity increases relative to that of the exciton emission as the wire diameter decreases due to a surface effect. [J. Lumines. 210, 128-134 (2019)]

Transient Absorption Spectroscopy

Extreme ultraviolet near-infrared (XUV–NIR) delay-dependent absorbance changes reflect a light-induced phase due to an NIR-field driven AC Stark shift of the excited states, as well as pathway interferences arising from couplings between neighboring states. As a novel aspect of molecular Iodomethane attosecond transient absorption spectroscopy (ATAS), pronounced differences were observed between the ATAS signatures of valence and Rydberg states - while the core-to-valence transitions carry the majority of the XUV oscillator strength, the core-to-Rydberg transitions are dominantly affected by a moderately strong, nonionizing NIR field. [J. Phys. Chem. Lett. 10, 265 (2018)]

Magnetization Dynamics High power, high repetiton rate OPCPA at MBI delivering CEP-stable, 7 fs pulses at 800 nm with up to 0.19 mJ of energy at a repetition rate of 100 kHz. Photo: Federico Furch

An optical inter-site spin transfer (OISTR) from Pt to Co was shown to be a dominant mechanism governing the ultrafast magnetization dynamics after optical excitation in a CoPt alloy. The helicity dependent absorption in the XUV range was shown to be directly related to changes of the transient spin-split density of states, linking the origin of OISTR to the available minority states above the Fermi level. [Nature Communications 11, 871 (2020)]

Atomic and Molecular Physics

The dielectric characteristics of transverse-optical (TO) phonon resonance are modified by the transverse electronic shift currents which accompany it, as was demonstrated after fourth-order nonlinear terahertz emission. Nonlinear signals due to interband shift currents and heavy-hole–light-hole polarizations are separated from Raman-induced TO phonon coherences, and the latter displayed a frequency upshift by some 100 GHz upon interband excitation of an electron-hole plasma. [Phys. Rev. Lett. 125, 027401 (2020)]

Projects performed by external users >>

Further application highlights

Lasers and Water

Expertise

Development of ultrashort and ultra-intense pulsed laser sources and laser-driven secondary radiation sources in a broad spectral range. Development of instrumentation and methods allowing to apply these sources in different research areas, ranging from atomic, molecular, and cluster physics to the physics of condensed matter, including magnetic materials and biological structures. Main research areas include attosecond physics, strong field physics and ultrafast phenomena in condensed matter.

Equipment offered to external users

By focusing the light moderately with a lens of long focal distance a plasma channel is formed. The generated colourful supercontinuum extends over the entire visible range. Photo: Dr. M. van Mörbeck-Bock

  • The BLiX laboratory offers a combination of laser-driven X-ray sources with state-of-the-art equipment for X-ray applications in microscopy, materials characterization and spectroscopy.
  • Attosecond research facilities, offering both high-power and high repetition rate lasers. The high-power facility is also equipped with a pump-probe setup and VMIS and XUV spectrometers. The high repetition rate (100 kHz) OPCPAs are combined with COLTRIMS detectors.
  • High harmonic beamlines offering a diverse range of output parameters
    • 1 kHz beamline for gas and condensed phase transient absorption experiments
    • two high flux beamlines (1 kHz, 100 Hz) that can be combined with a wide range of other laser pulses (UV to THz)
    • 3 kHz with up to 70 eV harmonics and polarization control (linear/circular) for pump-probe measurements of magnetic circular dichroism and magneto-optical Kerr effect in the XUV from solid thin film samples. Different sample environments (B,T) are available.
    • 100 kHz with up to 60 eV harmonics (trains or isolated attosecond pulses) combined with synchronized sub-10 fs 800 nm pulses for attosecond pump-probe experiments in the gas phase with electron-ion coincidence detection.
    • 1 kHz with up to 70 eV and a time-compensating monochromator for XUV-IR pump-probe experiments. Combined with VMI or TOF detectors for experiments in the gas phase or with aqueous solutions.
  • A THz/MIR laboratory for nonlinear THz experiments and THz/MIR pump-probe experiments, studying electrical transport phenomena under very high external fields in a time-resolved way and elucidating combined nonlinear optical and transport phenomena.
  • Starting in 2021, the NanoMovie lab will offer pump-probe spectroscopy and scattering on condensed matter samples with soft X-rays, extending into the water window.