Molecular chirality from the viewpoint of Mueller ellipsometry

Chirality - the non-superimposability of an object on its mirror image - shows its twists at all scales, from giant stellar galaxies to the electronic structure of materials. It enters into nearly every aspect of everyone's daily routine without acknowledging it. Yet, it governs the stereochemistry of all molecular processes in nature, making them life-forming or life-incompatible. It makes the knowledge of molecular spatial configuration essential in pharmacy, medicine, and biochemistry. Here, by combining spectroscopic Mueller matrix ellipsometry and suitable theory, we experimentally demonstrate and theoretically verify the advantage of the proposed method to determine dispersion characteristics of molecular chirality. We first show how the Mueller matrix relates to both macroscopic and microscopic physical quantities used commonly in description of molecular chirality. Next, we experimentally determine quantitative observables such as specific rotation (with sensitivity 0.001 rad) of limonene enantiomers. We believe that our findings may provide a deeper insight into the problematics and potentially extend the scope of the state-of-the-art Mueller matrix ellipsometry beyond the classical optics and photonics. The main contribution of our work is the use of a commercial ellipsometer in delicate optical activity measurements, demonstrating the flexibility and power of the method. It allows for the optical rotation of both limonene enantiomers measured over the spectral range 350 nm - 1600 nm for the first time.