Ultrafast optical rotation in chiral molecules

Sculpting sub-cycle temporal structures of optical waveforms allows one to image and even control electronic clouds in atoms, molecules and solids. In this presentation, I will show how the transverse spin component arising upon spatial confinement of such optical waveforms enables extremely efficient chiral recognition and control of ultrafast chiral dynamics. When an intense few-cycle, linearly polarized laser pulse is tightly focused into a medium of randomly oriented chiral molecules, the medium generates light which is elliptically polarized, with opposite helicities and opposite rotations of the polarization ellipse in media of opposite handedness [Ayuso et al, arXiv:2011.07873]. In contrast to conventional optical activity of chiral media, this new nonlinear optical activity is driven by purely electric-dipole interactions and leads to giant enantio-sensitivity in the near VIS-UV domain, where optical instrumentation is readily available. Adding a polarizer turns the rotation of the polarization ellipse into highly enantio-sensitive intensity of the nonlinear-optical response. Sub-cycle optical control of the incident light wave enables full control over the enantio-sensitive response. The proposed all-optical method not only enables chiral discrimination with extreme enantio-efficiency, but also ultrafast imaging and control of chiral dynamics using commercially available optical technology.