Spin noise spectroscopy of rubidium atomic gas under resonant and non-resonant conditions

Ma Jian¹, Shi Ping¹, Qian Xuan¹, Li Wei², Ji Yang^{1, †,}

Spontaneous spin noise in Rb at temperature T = 343 K. The laser is detuned Ω_D2 = 7 GHz from the D2 transition (5²S_1/2 to 5²P_3/2, 780 nm), ensuring negligible absorption. The laser power P = 300 μW. (a) D-line transition structure of Rb. (b) SNS in magnetic field B = 10 G. Inset: SNS traces in different magnetic field B. (c) SNS of ⁸⁷Rb in magnetic field B = 45 G. (d) Schematic diagram of the ground-state hyperfine levels of ⁸⁷Rb, nuclear spin I = 3/2.