The Effect of Laser Power on Electric Field Measurement Based on Rydberg Atom

Rydberg atom is a highly excited state atom, because of its extremely large polarizability and the frequency shift property of energy level under the action of external field, it is currently widely used for precise measurement of electric field. The main method of measurement is to obtain a stable electromagnetically induced transparency (EIT) spectrum by adjusting the frequency of the dual laser sources, detect the frequency shift of the EIT spectrum under the action of an external field, and convert it into electric field strength. This study found that the power of the laser source can also affect the effect of EIT spectroscopy. This paper first introduces the basic principle of the formation of the EIT effect, and derives the relationship between the laser power and the Rabi frequency through the formula, and combines the linear magnetic susceptibility formula to obtain the relationship between the laser power and the EIT effect. Then set up the experiment, use two-photon (852 nm probe light and 509 nm coupling light) excitation method to prepare cesium atomic state Rydberg atoms at room temperature, set four kinds of coupling light powers, and obtain the EIT effect under four kinds of coupling light powers, use each This EIT effect is used to measure the electric field, and its accuracy is compared, and the recommended value of coupling optical power is proposed. The research has guiding significance for the electric field measurement based on Rydberg atoms.