Optical detection of nuclear magnetization could provide improved sensitivity in site-specific spectroscopy and resolution in imaging of biomolecular systems. The discovery of nuclear spin optical rotation1 (NSOR), Faraday effect due to nuclear magnetization, marked the beginning of nuclear magneto-optic spectroscopy (NMOS). Later, optical shift between different molecular liquids has been detected2 (after theoretical prediction3) and alternative set-ups for enhanced measurements have been presented4 5. In theoretical phenomenology, means of obtaining high-resolution signals have been proposed3, and medium6 and heavy-atom7 effects investigated.
Also other phenomena lend themselves to NMOS. In Cotton-Mouton effects, ellipticity is induced to linearly polarized light due to interactions with nuclear quadrupole8, spin and an external magnetic field9, and two spins10 in the Voigt set-up, perpendicular to the optical beam. Here, partial orientation of the molecules arises, dependent on dynamic polarizability and the NMR quadrupole coupling, shielding, and spin-spin coupling, respectively. A promising method concerns spin-induced circular dichroism11, due to differential absorption of the left- and right-circularly polarized light. Finally, chiral recognition is proposed due to spin-induced magnetochiral birefringence12.