We report the development of a novel variant of cavity ring-down polarimetry using a continuous-wave laser operating at 532 nm for highly precise chiroptical activity and magnetometry measurements. The key methodology of the apparatus relies upon the external modulation of the laser frequency at the frequency splitting between non-degenerate left- and right-circularly polarised cavity modes. The method is demonstrated by evaluation of the Verdet constants of crystalline CeF3 and fused silica, in addition to the observation of gas- and solution-phase optical rotations of selected chiral molecules. Specifically, optical rotations of (i) vapours of alpha-pinene and R-(+)-limonene, (ii) mutarotating D-glucose in water, and (iii) acidified L-histidine solutions, are determined. The detection sensitivities for the gas- and solution phase chiral activity measurements are ~30 microdeg and ~120 microdeg over a 30 s detection period per cavity roundtrip pass, respectively. Furthermore, the measured optical rotations for R-(+)-limonene are compared with computations performed using the Turbomole quantum chemistry package. The experimentally observed optically rotatory dispersion of this cyclic monoterpene was thus rationalised via consideration of its room temperature conformer distribution as determined by the aforementioned single-point energy calculations.
Characterizing the nitrogen-vacancy center singlet transition and its phonon sideband for absorption-based room-temperature magnetometry
Fraunhofer Institute for Applied Solid State Physics IAF（弗劳恩霍夫应用固体物理研究所）；School of Science, RMIT University（皇家墨尔本理工大学理学院）；College of Staten Island (CUNY)（石溪学院（纽约市立大学））；National Institutes for Quantum Science and Technology (QST)（量子科学技术研究机构）；Physikalisches Institut, Universität Heidelberg（海德堡大学物理研究所）
