Optical multiple-frequency laser interference system for high-precision absolute gravity meter and application thereof

Abstract

The invention discloses an optical multiple-frequency laser interference system for a high-precision absolute gravity meter. The optical multiple-frequency laser interference system comprises a frequency stabilized laser, a collimation and beam expanding mirror, an adjustable reflector, a beam splitter, a reference prism, a faller prism, a horizontal liquid level, a reflecting prism, a diaphragm, a focusing lens and a photoelectric detector, wherein laser is emitted by the frequency stabilized laser, after passing through collimation and beam expanding mirror vertically downwards transmitted after being reflected by the adjustable reflector, and then split into a test light beam vertically downwards transmitted and a reference light beam horizontally transmitted to the right by the beam splitter, wherein the test light beam is shot to the horizontal liquid level after being reflected by the reference prism and the faller prism for many times, then returns according to the original light path after being reflected to join with the reference light beam to generate interference fringes, and the interference fringes pass through the opened diaphragm and are focused on the photoelectric detector by the focusing lens. The invention also discloses an absolute gravity meter adopting the system. According to the optical multiple-frequency laser interference system for the high-precision absolute gravity meter and the application thereof, the test precision can be improved for multiple times, and the direction of the test light beam can be simply and effectively adjusted to ensure that the direction is parallel to the direction of the gravity acceleration.

Description

technical field [0001] The invention relates to absolute gravity testing technology, in particular to an optical frequency-doubling laser interference system for a high-precision absolute gravimeter, which can accurately detect the falling position of a falling prism during the absolute gravity testing process. Background technique [0002] The gravity field is the basic physical field of the earth. High-precision absolute gravity observation data are widely used in the fields of geodesy, geophysics, geodynamics and seismology, as well as in the fields of military, aerospace, navigation, resource exploration and development engineering. There are a wide range of applications. At present, an absolute gravimeter is generally used to measure the acceleration of gravity. [0003] figure 1 It is a structural schematic diagram of an absolute gravimeter in the prior art. Such as figure 1 As shown, the absolute gravimeter in the prior art utilizes laser interferometry to accurat...

AI Technical Summary

Problems solved by technology

[0008] The test beam of the laser interference system in the prior art absolute gravimeter is only reflected once between the falling prism and the reference prism, and the sensitivity to the falling distance of the test prism is low; at the same time, the vertical direction adjustment of the test beam needs to be assisted by the telescopic system, and the system is relatively complicated. , and after the vertical direction adjustment of the test beam is completed, the horizontal liquid surface needs to be removed to start the absolute gravity test, which changes the state of the instrument and cannot monitor the vertical direction of the test beam in real time

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