Power Frequency Electric Fields Measurement Based On Electromagnetic Induced Transparent Spectrum Under Radio Frequency Field

The power frequency electric field refers to the electric field generated by a charge that changes sinusoidally with time at 50 Hz or 60 Hz.Power frequency electric field distribution exists in the environment of high-voltage and UHV transmission lines and power facilities.The development of high-sensitivity and high-precision power-frequency electric field off-line measurement technology is of great significance for high-voltage and UHV power safety detection.In the power frequency electric field measurement sensor widely used at present,its working principle is mainly based on the induced charge electrical measurement method and the optical electric field measurement method based on the electro-optic effect,but in actual use,both of them have considerable disadvantages.For example,it is difficult to apply the instrument based on the electrical measurement method to the live measurement on the spot,and it is difficult to accurately measure the strong electric field;the principle of the optical measurement method is that the electro-optical effect itself has temperature dependence,and the sensor based on this principle generally has the problem of temperature drift.In recent years,with the maturity of laser technology and the development of laser precise control technology for atomic quantum states,especially because Rydberg atoms have the characteristics of large polarizability and strong electric dipole moment relative to ground state atoms,they are weak Research on the highly sensitive measurement of electric field has aroused widespread attention at home and abroad.This article introduces we use two-photon(852 nm and 509 nm)excitation methods to achieve the preparation of the 53S_1/2Rydberg state of cesium atoms,and we observe the electromagnetic induced transparency spectroscopy of the 53S_1/2 Rydberg atom under the AC Stark effect caused by the radio frequency electric field.The relationship between the amplitude of the radio frequency electric field and the Stark frequency shift of electromagnetic induced transparency spectra was studied.Through the power frequency electric field amplitude modulation radio frequency electric field,the traceable measurement of the power frequency electric field field strength is realized,and the accurate measurement of the power frequency electric field frequency is obtained at the same time.The field strength sensitivity can reach 0.37 V/cm,and the amplitude measurement dynamic range can reach 37.2 d B,and the frequency measurement uncertainty is better than 0.1%.The main content of the article is composed of four chapters,namely:The first chapter is the introduction.First,it presents some of the properties of Rydberg atoms and the electromagnetically induced transparency effect of Rydberg atoms,and briefly introduction of Rydberg atoms application.Secondly,it introduces the principles of traditional power frequency electric field measurement methods,and the advantages and disadvantages of the traditional power frequency electric field measurement methods are compared,and the progress of quantum precision measurement made in the static electric field,microwave electric field,and terahertz electric field using Rydberg atoms is introduced.The second chapter is theory part.It mainly introduces the theoretical model of Rydberg atom electromagnetic induced transparency effect under the action of radio frequency electric field.First,the theory of three-level Rydberg atom electromagnetically induced transparency spectrum without external field is derived,and then the theory of Rydberg atom electromagnetically induced transparency spectrum under radio frequency field is deduced.Finally,the electromagnetically induced transparency spectrum under power frequency electric field with amplitude modulation is described.The third chapter is the part of the experimental device.The experimental device is divided into three modules,namely 852nm detection optical module,509nm coupling optical module and experimental operation module.In the article,the different uses of the two lasers used in the experiment and the frequency locking operation of the two lasers are introduced in detail,and the experimental operation objects are described in detail in the experimental operation module,such as the addition device of the radio frequency field and the power frequency field.The fourth chapter is the experimental results and analysis,this part mainly shows the electromagnetically induced transparency spectrum of Rydberg atoms under the action of radio frequency field and power frequency field.It also demonstrated the Stark frequency shift effect,and through the analysis of the Stark frequency shift effect,the polarization rate of the 53S_1/2cesium Rydberg atom was measured.For the measurement of the power frequency electric field,the emphasis is on the addition method and measurement scheme of the power frequency electric field,which realizes the accurate measurement of the power frequency electric field and verifies the feasibility and accuracy of the quantum measurement of the power frequency electric field;and in the last part of this chapter,it briefly introduces the use of 20S_1/2 cesium atom Rydberg state to try to measure the space radio frequency field.Innovations in this article:1.Quantum measurement is used to measure the power frequency electric fields.The precise measurement of the power frequency electric field amplitude is achieved by studying the electromagnetically induced transparency spectrum of cesium Rydberg atoms.The minimum detectable field strength is 0.37V/cm,and the dynamic range is 37.2d B.The traceable measurement of the power frequency electric field strength is realized.2.By amplitude modulating the radio frequency electric field,the power frequency electric field is added.It can not only study the change of electromagnetically induced transparent spectrum under the action of radio frequency field,but also realize the frequency measurement of power frequency electric field,and the frequency measurement uncertainty is better than 0.1%.