Measurement method and measurement device for intensity of microwave electric field

Abstract

The invention discloses a measurement method and measurement device for the intensity of a microwave electric field. The measurement method includes the steps of splitting a probe light generated by a first laser into two beams of identical probe light, one of which enters a rubidium cell and the other of which enters vacuum equipment; coupling light, which is generated by a second laser, entering the rubidium cell, coherently exciting hot atoms in the rubidium cell from a ground state to a rydberg state by the coupling light and the probe light, and realizing electromagnetically induced transparency in an atomic vapor chamber; applying a microwave electric field generated by a microwave source onto the hot atoms, and coupling another adjacent rydberg state onto a three-level EIT system to form a four-level system; and respectively probing the two ways of transmission light emitted from the rubidium cell and the vacuum equipment, determining the time difference of the two ways of transmission light by analyzing a dispersion relation between the two ways of transmission light, and thus obtaining the intensity of the microwave electric field.

Description

technical field [0001] The invention relates to a microwave electric field intensity measurement method and a measurement device. Background technique [0002] In 2012, the Shaffer research group of Oklahoma University in the United States cooperated with the Pfau research group of Stuttgart University in Germany for the first time to use Rydberg atoms EIT (Electromagnetically Induced Transparency, electromagnetically induced transparency) and AT (Autler-Townes) The measurement is transformed into an optical frequency measurement, and the microwave electric field measurement is realized experimentally, and the minimum electric field strength measured is 8μVcm -1 , with a sensitivity of 30μVcm -1 Hz -1 / 2 , far superior to the traditional dipole antenna microwave electric field meter. Then in 2013, based on the original experiment, they realized the measurement of the microwave polarization direction, and the polarization measurement accuracy was 0.5°. In 2014, the Nationa...

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Problems solved by technology

[0003] However, according to the current experimental measurement and theoretical analysis, the microwave electric field detection technology based on AT splitting, when the microwave electric field is weak, the detection light transmission peak is only slightly depressed and has not yet split. The detection is difficult; at the same time, the width of the detection light transparent window is affected by factors such as laser line width, transition broadening, shot noise and Rydberg atom decoherence, and it is impossible to achieve precise measurement of the extremely weak microwave electric field

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