Influence of pump intensity on atomic spin relaxation in a vapor cell*

Abstract

Atomic spin relaxation in a vapor cell, which can be characterized by the magnetic resonance linewidth (MRL), is an important parameter that eventually determines the sensitivity of an atomic magnetometer. In this paper, we have extensively studied how the pump intensity affects the spin relaxation. The experiment is performed with a cesium vapor cell, and the influence of the pump intensity on MRL is measured at room temperature at zero-field resonance. A simple model with five atomic levels of a Λ-like configuration is discussed theoretically, which can be used to represent the experimental process approximately, and the experimental results can be explained to some extent. Both the experimental and the theoretical results show a nonlinear broadening of the MRL when the pump intensity is increasing. The work helps to understand the mechanism of pump induced atomic spin relaxation in the atomic magnetometers.

Improvement of the short-term stability of atomic fountain clock with state preparation by two-laser optical pumping*

“…[6] Optical pumping (OP), redistributing atomic populations among the hyperfine-structure levels by selective absorption of lights, has attracted extensive attention in atomic physics and related fields, such as atomic clocks and atomic magnetometers. [7,8] Generally, circularly polarized lights are used as OP for noble-gas nuclei in the field of magnetic resonance imaging and for alkali atoms in atomic orientation and magnetic resonance to accumulate more atoms in the stretched state. [9,10] And now, OP has also been used in the atomic fountain clocks with π-polarized laser to accumulate atoms in the |m F = 0 state.…”