Paper: New J. Phys.


The Arndt Group published a new article on "Isotope-selective high-order interferometry with large organic molecules in free fall" in New Journal of Physics

Interferometry in the time domain has proven valuable for matter-wave based measurements. This concept has recently been generalized to cold molecular clusters using short-pulse standing light waves which realized photo-depletion gratings, arranged in a time-domain Talbot–Lau interferometer (OTIMA). Here we extend this idea further to large organic molecules and demonstrate a new scheme to scan the emerging molecular interferogram in position space. The capability of analyzing different isotopes of the same monomer under identical conditions opens perspectives for studying the interference fringe shift as a function of time in gravitational free fall. The universality of OTIMA interferometry allows one to handle a large variety of particles. In our present work, quasi-continuous laser evaporation allows transferring fragile organic molecules into the gas phase, covering more than an order of magnitude in mass between 614 amu and 6509 amu, i.e. 300% more massive than in previous OTIMA experiments. For all masses, we find about 30% fringe visibility.

Read more: here.

OTIMA interferometry with large organic molecules in the presence of gravity. Massive porphyrin derivatives are evaporatedfrom the target translation stage (T) upon absorption of an intense green source laser (SL) beam, which is chopped by either a slottedrotating disk or an acousto-optic modulator (AOM), depending on the experiment.