Enhanced chiral discrimination in mass spectrometry with orbital angular momentum beams
- Haritha Venugopal
- Parishkrith Aravind
- Angitha Sajeevan
- Sanket Sen
- Abhisek Sinha
- Sucharita Giri
- Gopal Dixit
- Ram Gopal
- Vandana Sharma
2026-06-05
Chirality, the absence of mirror symmetry, is a fundamental property observed from subatomic particles to molecules and macroscopic systems. Distinguishing molecular mirror images (enantiomers) is essential in pharmaceuticals and molecular diagnostics. Traditional chiral spectroscopy relies on chiral light carrying spin angular momentum (SAM). Here, we demonstrate that twisted femtosecond laser beams carrying orbital angular momentum (OAM), combined with SAM and mass spectrometry, can enhance chiral selectivity by up to fourfold. Using the enantiomers (1S)-(-)- and (1R)-(+)-Camphor, we observe strong enantioselective ionization and fragmentation with laser pulses of a few hundred femtoseconds and energies of several hundred μJ. The interplay of SAM and OAM improves the sensitivity and selectivity of chiral mass spectrometry without chemical derivatization, offering a scalable approach for probing molecular handedness in complex chemical and biological systems.