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High-order harmonic generation in an organic molecular crystal
Falk-Erik Wiechmann1,2, Samuel Schöpa1, Lina Bielke1
1Institute for Physics, University of Rostock, Rostock, Germany.
Nature Communications
|November 10, 2025
Summary
High-order harmonic generation (HHG) in organic molecular crystals like pentacene reveals electronic structure. This technique probes intermolecular interactions, offering new insights into organic electronics.
Area of Science:
- Condensed matter physics
- Materials science
- Quantum optics
Background:
- High-order harmonic generation (HHG) is crucial for studying matter's electronic and ultrafast dynamics.
- HHG has been extended from gases to condensed matter for all-optical investigations.
- Organic molecular crystals are promising for electronics due to unique properties.
Purpose of the Study:
- To demonstrate HHG in thin organic molecular crystals with aligned molecules.
- To investigate pentacene as a model system for HHG.
- To explore HHG's sensitivity to intermolecular interactions in organic crystals.
Main Methods:
- Experimental demonstration of HHG in pentacene crystals.
- Varying laser intensities to achieve high harmonic orders (up to 17th).
- Analyzing harmonic yield dependence on laser polarization.
Main Results:
- Efficient HHG up to the 17th order was achieved in pentacene crystals.
- Harmonic yield strongly depends on intermolecular interactions and laser polarization.
- Higher harmonic orders are sensitive to nearest- and next-nearest-neighbor couplings.
Conclusions:
- HHG is a viable tool for probing the electronic structure of organic molecular crystals.
- Weaker intermolecular interactions in organic crystals require higher harmonic orders for structural resolution.
- HHG enhances all-optical techniques for studying complex organic materials.
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