• Acta Photonica Sinica
  • Vol. 52, Issue 9, 0902001 (2023)
Ke LI1、2, Jianfei TIAN1、2, Hao ZHANG1、2, Mingyong JING1、2, and Linjie ZHANG1、2、*
Author Affiliations
  • 1State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Laser Spectroscopy,Shanxi University,Taiyuan 030006,China
  • 2Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China
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    DOI: 10.3788/gzxb20235209.0902001 Cite this Article
    Ke LI, Jianfei TIAN, Hao ZHANG, Mingyong JING, Linjie ZHANG. Microwave Electric Fields Measurement with One-dimensional Standing-wave Fields Based on Rydberg Atoms[J]. Acta Photonica Sinica, 2023, 52(9): 0902001 Copy Citation Text show less

    Abstract

    Due to the large distance between the electrons and the nucleus and the large electric dipole moment, the interatomic interaction of the Rydberg atoms are weaker than those of the ground-state atoms. Therefore, the external electric field has a greater influence on the Rydberg atoms. This property leads to the fact that the Rydberg atoms is extremely sensitive to the external electric field. Therefore, electric field measurement based on Rydberg atoms is a hot spot, especially in microwave electric field measurement. In addition, thanks to the long lifetime of the Rydberg atoms, there are possibilities to achieve higher sensitivity beyond classic electric dipole antenna.Enhancement measurement of microwave electric field is demonstrated based on the Electromagnetically Induced Transparency (EIT) effect of the Rydberg atoms, in which a one-dimensional standing wave of coupling light field is formed. This paper presents comprehensive research for measuring microwave electric field based on the coherent enhancement of a one-dimensional standing wave field of coupling light based on the electromagnetic induction effect of Rydberg atoms. A four-level system of cesium atoms at room temperature is constructed. At first, the cesium atoms in the ground-state (6S1/2) are excited to the immediate state (6P3/2) by a diode laser (probe light, ~852 nm). Secondly, a 510 nm laser (coupling light) exits the immediate state atoms to the Rydberg state. The transmission of the probe light, which is derived from the electromagnetic induced transparency effect, is recorded. In an atom vapor cell with an antireflection film coating at the wavelength of coupling light, a one-dimensional standing wave field of coupling light is achieved using a mode-matching reflection optical path. The influence of the coherent enhancement of the one-dimensional standing wave coupling light field on the electromagnetically induced transparency transmission is observed and analyzed. Then, the cesium atoms are coupled with the nearby Rydberg state by the incoming microwave electric field. The microwave electric field in the four-level atomic system causing a splitting of the transmission spectrum of probe laser which is known as Autler-Townes splitting. The coherent enhancement of the one-dimensional standing wave coupling light field on the EIT-AT splitting spectrum is observed, and the strength of microwave electric field with amplitude modulation is measured using the spectrum analyzer.The experimental results have shown that the amplitude and linewidth of the Rydberg electromagnetically induced transparency spectrum is enhanced significantly, in which the one-dimensional standing wave coupling light field is formed. Compared to increasing the output power of the coupling laser, the measurement of amplitude-modulated microwave electric field is investigated with the one-dimension standing wave in detail. The results show that for the lower-power microwave electric field, the signal-to-noise ratio is improved by about 4 dB and the instantaneous bandwidth is increased by 1.38 times in the one-dimensional standing wave field. A flatter frequency response is obtained for higher-power microwave electric field, while an apparent bimodal frequency response curve is observed without a standing wave field. The coherent power enhancement at the propagating direction of coupling light and the detuning of the probe and coupling light induced by Doppler effect are responsible for improving the signal-to-noise ratio and flattening frequency response curve. The precision measurement of microwave electric field is attributed to a frontier research field that can be applied to developing microwave communication and radar. The coherent enhancement of Rydberg atoms EIT one-dimensional standing wave coupling light field can be adopted as a new method to develop the electric field probe (sensor) with low power consumption, flat frequency response curve and high dynamic range, which will be significant for the development and the application of the corresponding metrological standard.
    Ke LI, Jianfei TIAN, Hao ZHANG, Mingyong JING, Linjie ZHANG. Microwave Electric Fields Measurement with One-dimensional Standing-wave Fields Based on Rydberg Atoms[J]. Acta Photonica Sinica, 2023, 52(9): 0902001
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