Single-frequency polarized laser interferometer and optical-path-multiplying high-sensitivity laser strain meter

Abstract

The invention relates to a single-frequency polarized laser interferometer and an optical-path-multiplying high-sensitivity laser strain meter. A first single-frequency polarized laser interferometer which is arranged on a first bed rock and a first measurement reflector form an integral single-frequency polarized laser interferometer; the first measurement reflector is connected with a head end of a measurement base line through a calibration and limit device; a reflector limit device is arranged at the tail end of the measurement base line; a second measurement reflector is arranged in the reflector limit device; the second measurement reflector and a second single-frequency polarized laser interferometer which is fixed on a second bed rock form another integral single-frequency polarized laser interferometer; a suspension system is arranged in the middle of the measurement base line; and the first single-frequency polarized laser interferometer, the second single-frequency polarized laser interferometer and the calibration and limit device are connected with a signal recording and processing system through signal connecting wires. The single-frequency polarized laser interferometer and the optical path multiplying high-sensitivity laser strain meter are high in measurement precision and simple in structure, and can be widely used in the field of geophysics research such as observation for crustal strain and solid tide and acquisition of precursor information before earthquakes.

Description

technical field [0001] The invention relates to a laser interferometer and a laser strain gauge mainly composed of the laser interferometer. It specifically relates to an optical path structure layout and a mechanical fixing installation structure of a laser interferometer used in the technical field of geoscience observation. Background technique [0002] The telescopic measuring instrument is an instrument for precisely measuring the relative change of the distance between two points in the crustal rock mass. It has important applications in the fields of observing crustal strain and solid tides, as well as studying the process of earthquake breeding and obtaining earthquake precursors. [0003] Since the American seismologist H. Benioff developed the first valuable quartz extensometer in 1935, the United States, Britain, the former Soviet Union, Japan, Belgium, Germany and other countries have successively developed high-sensitivity extensometers. instrument. The sensit...

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Problems solved by technology

[0008] The displacement sensor in the extensometer invented at present mainly adopts the eddy current displacement sensor, the differential transformer displacement sensor, or the capacitance displacement sensor, among which the best displacement resolution of the first two is about 1nm; while the capacitance displacement sensor has a better resolution , can reach 0.01nm, but the disadvantages are that the parasitic capacitance and distributed capacitance have a great influence on the sensitivity and measurement accuracy, the output is non-linear, the connection circuit is complicated, and it is affected by humidity and electromagnetic interference. It is not very suitable for the reliability of the extensometer. High stability requirements, long-term work and other practical occasions

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