Double laser hit to probe vibrations

Lasers can both initiate and investigate a molecular change to shed light on how molecules vibrate.

Roger Miller and his colleagues at University of North Carolina, US, are pioneering the double laser method with molecules dissolved in helium nanodroplets.

A laser is used to photoexcite the molecule in the helium droplet, then a second laser subsequently probes any photochemical changes in the molecule. Where simple molecules after excitation relax in a simple step, more complex molecules take more steps to return to their ground state, but these steps are poorly understood.

Miller’s method could offer insight into these processes and he hopes to develop it to probe biomolecule-water interactions in nature. The idea is to apply his fundamental findings to biological systems. ’The exquisite structural complexities that exist in nature pale when compared to the dynamical diversity that is being uncovered by modern methods,’ he says.

Katharine Sanderson