Aarhus Universitets segl

Instruments

SurfLab has a wide array of ultrafast laser systems to enable us to study complex phenomena in chemical and biological systems. Our laser laboratory has over 25 m2 of optical tables, six different femtosecond laser systems and more than eight different user endstations. This allows us to maintain experimental setups for consistent data acquisition, while also reserving some endstations to develop and build further state-of-the-art experiments.

Sum frequency generation (SFG) spectroscopy is a surface-sensitive vibrational spectroscopy that allows us to selectively study the distinct and diverse behaviour of molecules at interfaces. Our lab contains multiple home-built SFG spectrometers to study a wide range of samples.


Reflection SFG spectroscopy

The “Work Horse” reflection SFG spectrometer based on a Ti:Sa Coherent Astrella laser system (35 fs, 800 nm, 7 mJ/pulse @ 1 kHz) and Topas mid-IR OPA and DFG mixer unit.

Types of samples:
Air/water interface, electrode/electrolyte interface, peptides, proteins, lipid membranes, self-assembled monolayers, metals, minerals, thin films and even animal tissue (snake skin, beetle heads, gecko toes, etc.).


Angle-resolved sum frequency scattering spectrometer

Designed for detecting sum frequency scattered light at a wide range of angles, based on a Light Conversion Pharos laser system (70 fs, 1030 nm, 1.8 mJ/pulse @ 10 kHz), along with a second harmonic bandwidth compressor and Orpheus/Lyra mid-IR OPA and DFG units.

Types of samples:
Nanoplastics, aerosols, emulsions and other particle surfaces.

Two additional endstations for exciting new SFG setups, including a heterodyne-detected 2DSFG spectrometer.


Two-dimensional infrared spectrometer

At SurfLab we use a PhaseTech 2DIR spectrometer to record the IR analogue of 2D-NMR. From this kind of spectrum, we can gain detailed information on vibrational couplings and dynamics in both solid and liquid samples with femtosecond time resolution. This allows us to gain deep insights on the secondary structures of proteins and their aggregation.

Types of samples:
Solutions, thin films and suspensions, including proteins in solution, on nanoparticles and dried films as well as small molecules related to the origin of life.


Transient absorption spectroscopy

Our lab has recently acquired a Harpia spectrometer from Light Conversion for ultrafast transient absorption spectroscopy in the UV, visible and NIR. This allows us to follow the very fast dynamics in chemical and biological systems on the femtosecond to nanosecond timescale.

Types of samples:
Thin films, suspensions and solutions, including a windowless waterfall flowing geometry.


Mid-IR Transient absorption spectroscopy

Our lab has a home-built Mid-IR transient absorption spectrometer based on a femtosecond Titanium:Sapphire laser system from Spectra Physics/Clark-MXR and an Optical Parametric Amplifier from Light Conversion. The spectrometer allows us to follow the very fast dynamics in chemical and biological systems on the femtosecond to nanosecond timescale.

Types of samples:
Windowless wire-guided aqueous samples in flow geometry.


Complementary techniques

We also have many other additional instruments to complement our laser spectroscopy including:

  • FTIR, UV-Vis and Raman spectrometers for recording linear spectra of samples.
  • Height sensors, temperature-controlled sample holders and motorized rotation stages for SFG experiments
  • A home-built Dynamic Light Scattering instrument for measuring nanoparticle sizes.
  • A Kibron Langmuir trough, with tensiometer and Langmuir-Blodgett film apparatus for preparing lipid mono- and bilayers and transferring them to substrates.
  • A KSV NIMA Brewster’s Angle Microscope for studying heterogeneity in monomolecular films at the air/water interface.