Chiral optical forces in a slot waveguide for the separation of molecules in gas

Chiral optical forces present an exciting avenue into the separation of enantiomers in an all-optical fashion. Previous works have addressed the feasibility of separating nanoparticles exhibiting relatively large chirality parameter values. However, from a practical perspective, the real challenge is to separate chiral molecules that typically display extremely low chirality. In this work, we explore via numerical simulations and analytical calculations the feasibility of the separation of chiral molecules by using guided light in a dielectric slot waveguide. Our results suggest that it is possible to separate [6]helicene enantiomers suspended in gas in time scales of the order of less than a day when applying optical powers of 100 mW at a wavelength of 332 nm.