A closed-loop signal acquisition method in an optical interferometric gravimeter

Abstract

The invention discloses a closed-loop signal collection method of an optical interference gravimeter. A signal collection device having a frequency-stabilizing laser source, a first beam splitter, a faller prism, a reference prism, two parallel planar mirrors, a second beam splitter, a photoelectric detector, a phase modulator and a PC upper computer or an oscilloscope is adopted. The photoelectric detector transmits optical signals collected in the falling process of the faller prism to the phase modulator as feedback signals. The phase modulator outputs a bias phase. The phase difference between light and reference light is tested in the falling process of a compensation faller, replacement is carried out when the phase compensation is up to 2[pi], and the phase compensation process is repeated. The phase difference introduced by the phase modulator and a voltage value generating the phase difference are used as the signal data obtained finally. According to the invention, the data processing is simple, and the measuring sensitivity is high.

Description

technical field [0001] The invention relates to a closed-loop signal acquisition method in an optical interference gravimeter, and is especially suitable for a signal acquisition system of an absolute gravimeter. Background technique [0002] At present, in optical interferometric gravimeters, including absolute gravimeters, since the signals to be collected are in the order of megahertz, the signal collection method commonly used is: after the optical signal is converted into an electrical signal by a photodetector, it is obtained by an oscilloscope. The stripe data is then transferred to the PC for processing; or use a photodetector plus a high-speed acquisition card to directly collect data and send it to the PC for processing. Although the acquisition process of these two data acquisition methods is relatively simple, the measurement sensitivity of the entire optical interference system is not fully utilized, which will bring errors to the final measurement data, and the...

AI Technical Summary

Problems solved by technology

Although the acquisition process of these two data acquisition methods is relatively simple, the measurement sensitivity of the entire optical interference system is not fully utilized, which will bring errors to the final measurement data, and the processing of a large number of fringe data is very complicated.

Images