Swar Maheswar, Roy Dibyendu, D Dhanalakshmi, Chaudhuri Saptarishi, Roy Sanjukta, Ramachandran Hema
Opt Express. 2018 Nov 26;26(24):32168-32183. doi: 10.1364/OE.26.032168.
We explore the applications of spin noise spectroscopy (SNS) for detection of the spin properties of atomic ensembles in and out of equilibrium. In SNS, a linearly polarized far-detuned probe beam on passing through an ensemble of atomic spins acquires the information of the spin correlations of the system which is extracted using its time-resolved Faraday-rotation noise. We measure various atomic, magnetic and sub-atomic properties as well as perform precision magnetometry using SNS in rubidium atomic vapor in thermal equilibrium. Thereafter, we manipulate the relative spin populations between different ground state hyperfine levels of rubidium by controlled optical pumping which drives the system out of equilibrium. We then apply SNS to probe such spin imbalance non-perturbatively. We further use this driven atomic vapor to demonstrate that SNS can have better resolution than typical absorption spectroscopy in detecting spectral lines in the presence of various spectral broadening mechanisms.
我们探索了自旋噪声光谱学（SNS）在检测处于平衡态和非平衡态的原子系综的自旋特性方面的应用。在SNS中，一束线性偏振的远失谐探测光束穿过原子自旋系综时，会获取系统自旋关联的信息，该信息通过其时间分辨的法拉第旋转噪声来提取。我们在热平衡的铷原子蒸气中使用SNS测量各种原子、磁性和亚原子特性，并进行精密磁测量。此后，我们通过可控光抽运操纵铷不同基态超精细能级之间的相对自旋布居数，从而使系统偏离平衡态。然后，我们应用SNS以非微扰方式探测这种自旋不平衡。我们进一步利用这种受驱动的原子蒸气来证明，在存在各种光谱展宽机制的情况下，SNS在检测光谱线时可以比典型的吸收光谱具有更好的分辨率。
