Ultrafast ion detector for the study of molecular chirality

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NEED and URGENCY. One of my ongoing research programs is on optical detection, manipulation and separation of chiral molecules. To study molecular chirality, we use an unconventional light source - a unique laser instrument known as an "optical centrifuge". In a series of recent proof-of-principle experiments, we demonstrated that a laser centrifuge may offer a long-sought universal (i.e. independent on the chemical structure) method for the detection and separation of chiral molecules according to their handedness, much like mechanical centrifuges separate molecules according to their mass. However, at this time, poor sensitivity of our ion detector prohibits any further in-depth studies of the optically centrifuged chiral molecules, preventing us from developing this important discovery into much needed practical applications. Upgrading our ion detector with an advanced "time stamping" capability, requested in this application, will immediately boost its sensitivity by a few orders of magnitude, allowing us to take full advantage of our unique laser technology. RESEARCH PROGRAM. Similar to a chemical reaction between two chiral molecules, an interaction of a chiral molecule with light depends on the handedness of both the molecular and optical "reagents". Traditionally, the chirality of the interacting photons has been provided by their circular polarization. My research program is based on an alternative form of a chiral light field - the field of an optical centrifuge. The centrifuge is a laser pulse whose linear polarization rotates at much slower angular frequencies than the polarization of a circularly polarized light. As a result, the centrifuge engages the rotational (rather than the electronic) degree of freedom of a chiral molecule, forcing the molecule to rotate regardless of its chemical composition or electronic resonances. On the other hand, the two opposite enantiomers of the same chiral molecule are spun by the optical centrifuge in distinctly different ways, as recently shown by my group. Our goal is to develop new methods not only for the universal detection of chiral molecules with non-resonant photons, but also for the enantio-selective control of chiral dynamics and manipulation of chiral molecules with laser light. ADVANCEMENT of KNOWLEDGE and TRAINING. Despite large investments and the vital need, no chemical or physical process is known to provide a universal method of detecting and separating molecular enantiomers, which would work independently of their specific molecular structure. The proposed study of chiral molecules in the optical centrifuge offers a promising laser-based approach to achieve this important goal. The requested upgrade of our ion detector with a very advanced and largely unfamiliar "time stamping" technology will provide our HQP with a unique research experience and a very marketable skill, applicable to both the academic and industrial sectors, where ion-based detectors are widely used.