arXiv subjects

Riaan P. Schmidt

Publications and source records attributed to Riaan P. Schmidt.

2 recordsLinked to original sources

arXiv2026

Spatio-spectral vector light created by optical activity in rubidium vapor

We demonstrate a pump-probe scheme in which an atomic vapor is optically pumped with circularly polarized light and probed with a vector vortex beam. The pump induces a macroscopic magnetization in the medium, which gives rise to frequency-dependent circular dichroism and birefringence. The vortex probe, characterized by spatially varying polarization, maps this optical activity onto the spatial structure of the transmitted light, thereby generating correlations between the frequency, polarization, and spatial degrees of freedom. Measuring the intensity profile in a suitable polarization component then allows us to perform spatially resolved polarization spectroscopy. We demonstrate the translation of frequency shifts into an image rotation, observing on resonance a rotation in the order of 98 mrad per MHz. These findings may find applications in high-precision spectroscopy, magnetometry, and the generation of hybrid entanglement.

physics.atom-ph↗

arXiv2024

Interaction of vector light beams with atoms exposed to a time-dependent magnetic field

During recent years interest has been rising for applications of vector light beams towards magnetic field sensing. In particular, a series of experiments were performed to extract information about properties of static magnetic fields from absorption profiles of light passing through an atomic gas target. In the present work, we propose an extension to this method for oscillating magnetic fields. To investigate this scenario, we carried out theoretical analysis based on the time-dependent density matrix theory. We found that absorption profiles, even when averaged over typical observation times, are indeed sensitive to both strength and frequency of the time-dependent field, thus opening the prospect for a powerful diagnostic technique. To illustrate this sensitivity, we performed detailed calculations for the $5s \;\, {}^2S_{1/2}$ ($F=1$) $-$ $5p \;\, {}^2 P_{3/2}$ ($F=0$) transition in rubidium atoms, subject to a superposition of an oscillating (test) and a static (reference) magnetic field.

physics.atom-ph↗