Polarization enhancement based on holographic recording modulation in rubidium vapor

Spin polarization is an important parameter of magnetometers, and is essential for enhancing the stability and sensitivity of magnetic field measurements. The interference light field formed by the small angle interference of two right-handed circularly polarized beams remains right-handed circularly polarized, which can polarize alkali metal atoms and enable holographic recording. To analyze the effect of holographic modulation on spin polarization, we first performed holographic recordings in two cells: one containing pure ⁸⁷Rb vapor, and the other containing ⁸⁷Rb atoms, N₂ and He, which is commonly used in atomic magnetometers. Holographic recordings from the optical field amplification and the influences of signal light detuning and temperature on the hologram were experimentally studied. The diffraction efficiency can be obtained by detecting the intensity of the diffracted beam, and the diffraction efficiency reached 5% in the ⁸⁷Rb-He-N₂ cell. Measurements of the spin polarization, demonstrated that holographic record modulation effectively enhanced spin polarization in the two cells, and the presence of a buffer gas contributed to spin polarization. This method increased the polarizability of the signal light to the atoms by 4.3% and is expected to achieve higher polarizability through the fine-tuning of the light field. The results show that the holographic light field may aid in further improving the sensitivity of atomic magnetometers under the premise of constant signal intensity.