Precise and rapid detection of optical activity for accumulative femtosecond spectroscopy

Analytic Optimization of Near-Field Optical Chirality Enhancement

We present an analytic derivation for the enhancement of local optical chirality in the near field of plasmonic nanostructures by tuning the far-field polarization of external light. We illustrate the results by means of simulations with an achiral and a chiral nanostructure assembly and demonstrate that local optical chirality is significantly enhanced with respect to circular polarization in free space. The optimal external far-field polarizations are different from both circular and linear. Symmetry properties of the nanostructure can be exploited to determine whether the optimal far-field polarization is circular. Furthermore, the optimal far-field polarization depends on the frequency, which results in complex-shaped laser pulses for broadband optimization.

Optical discrimination of racemic from achiral solutions

We demonstrate purely optical discrimination between achiral and racemic solutions by selectively triggering an asymmetric photoreaction with femtosecond laser pulses.