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Welcome to the Nonlinear Chemical Imaging Group
Our group focusses on characterising the heterogeneity in chemical structure at interfaces using ultrafast nonlinear microscopy techniques, with the aim to connect these lateral microscopic variations to the macroscopic physical properties.
Latest News:
New Archive Paper: Multipole Contributions in SFG
May 2025
We have a new archive paper led by the group of Roland Netz wherein we disentangle the electric and magnetic multipole contributions to the SFG spectra from the air-water interface. This work shows the importance of including electric quadrupole and magnetic dipole contributions for the correct assignment of the spectral line-shapes. You can read more here.
New Archive Paper: Molecular Twisting in Interfacial Water
May 2025

We have a new archive paper wherein we revise the current understanding of the molecular structure at the air-water interface by demonstrating that the molecular twist angle is just as important as the tilt angle in defining the preferential molecular orientation. This is achieved by applying depth-resolved SFG-DFG spectroscopy in combination with MD simulations performed by the group of Roland Netz to probe the H-O-H bending mode and characterise the layer-dependent structural motifs at the interface. You can read more here.
Our Work Presented at ECONOS 2025
Apr 2025
Our recent collaborative work on using SFG microscopy to image CVD-grown hexagonal Boron Nitride (hBN) monolayers was presented at ECONOS 2025 in Meudon, France. It was great to see a wide range of talks and posters and have thrilling discussions with our colleagues in the nonlinear optical spectroscopy community from all across Europe.
Our New Paper Featured in Faraday Discussion
Apr 2025
Our recent paper using azimuthal-scanning phase-resolved SFG microscopy to investigate the effect of phosphatidylserine (PS) lipid exposure on the membrane packing structure was presented at the recent Faraday Discussion on ‘Structural and Functional Asymmetry of Plasma Membranes’. Overall there were many exciting papers presented at the conference and we were pleased to engage in deep discussions with our colleagues on our work. Thanks to the organisers for putting on an excellent event! You can find the link to our paper here.
New Archive Paper: Sum-Frequency Imaging of hBN Monolayers
Apr 2025

We have a new archive paper based on our recent work on imaging CVD-grown hexagonal Boron Nitride (hBN) monolayers with phonon-enhanced SFG microscopy. In this work we showcase the potential of SFG microscopy for imaging these otherwise optically elusive monolayers and, using rotational-dependent measurements, fully characterise their crystallographic structures. You can read more here.
As this work was a huge collaborative effort spanning several others from the FHI, particularly the Paarmann and Thämer groups, as well as colleagues from FU Berlin and Vanderbilt University in the US, I would like to thank all of the coauthors for their work in making this possible.
As this work was a huge collaborative effort spanning several others from the FHI, particularly the Paarmann and Thämer groups, as well as colleagues from FU Berlin and Vanderbilt University in the US, I would like to thank all of the coauthors for their work in making this possible.