Optical polarizabilities of large molecules measured in near-field interferometry

TL;DR

This paper demonstrates a novel matter wave interferometry method to measure the optical polarizability of large molecules like fullerenes at 532 nm, providing a new experimental approach for molecular characterization.

Contribution

It introduces a new interferometric technique using material and optical gratings to directly measure molecular polarizability at a specific wavelength.

Findings

Measured polarizability of C60 and C70 molecules agrees with literature values.

Validated the interferometry method as effective for molecular polarizability measurement.

First proof-of-principle experiment for this measurement approach.

Abstract

We discuss a novel application of matter wave interferometry to characterize the scalar optical polarizability of molecules at 532 nm. The interferometer presented here consists of two material absorptive gratings and one central optical phase grating. The interaction of the molecules with the standing light wave is determined by the optical dipole force and is therefore directly dependent on the molecular polarizability at the wavelength of the diffracting laser light. By comparing the observed matter-wave interference contrast with a theoretical model for several intensities of the standing light wave and molecular velocities we can infer the polarizability in this first proof-of-principle experiment for the fullerenes C60 and C70 and we find a good agreement with literature values.