Precise measurement of variations in the local gravitational acceleration is valuable for natural hazard forecasting,prospecting,and geophysical studies.Common issues of the present gravimetry technologies include the...Precise measurement of variations in the local gravitational acceleration is valuable for natural hazard forecasting,prospecting,and geophysical studies.Common issues of the present gravimetry technologies include their high cost,high mass,and large volume,which can potentially be solved by micro-electromechanical-system(MEMS)technology.However,the reported MEMS gravimeter does not have a high sensitivity and a large dynamic range comparable with those of the present commercial gravimeters,lowering its practicability and ruling out worldwide deployment.In this paper,we introduce a more practical MEMS gravimeter that has a higher sensitivity of 8μGal/√Hz and a larger dynamic range of 8000 mGal by using an advanced suspension design and a customized optical displacement transducer.The proposed MEMS gravimeter has performed the co-site earth tides measurement with a commercial superconducting gravimeter GWR iGrav with the results showing a correlation coefficient of 0.91.展开更多
In this paper,we present a suppression method for the thermal drift of an ultra-stable laser interferometer.The detailed analysis on the Michelson interferometer indicates that the change in optical path length induce...In this paper,we present a suppression method for the thermal drift of an ultra-stable laser interferometer.The detailed analysis on the Michelson interferometer indicates that the change in optical path length induced by temperature variation can be effectively reduced by choosing proper thickness and/or incident angle of a compensator.Taking the optical bench of the Laser Interferometer Space Antenna Pathfinder as an example,we analyze the optical bench model with a compensator and show that the temperature coefficient of this laser interferometer can be reduced down to 1 pm/K with an incident angle of 0.267828 rad.The method presented in this paper can be used in the design of ultra-stable laser interferometers,especially for space-based gravitational waves detection.展开更多
基金This work was partially supported by The National Key Research and Development Program of China(Grant No.2017YFC0601603)the Natural Science Foundation of China(Grant Nos.41874089&61871439)the HUST Key Innovation Team Foundation for Interdisciplinary Promotion(Grant No.2016JCTD102)。
文摘Precise measurement of variations in the local gravitational acceleration is valuable for natural hazard forecasting,prospecting,and geophysical studies.Common issues of the present gravimetry technologies include their high cost,high mass,and large volume,which can potentially be solved by micro-electromechanical-system(MEMS)technology.However,the reported MEMS gravimeter does not have a high sensitivity and a large dynamic range comparable with those of the present commercial gravimeters,lowering its practicability and ruling out worldwide deployment.In this paper,we introduce a more practical MEMS gravimeter that has a higher sensitivity of 8μGal/√Hz and a larger dynamic range of 8000 mGal by using an advanced suspension design and a customized optical displacement transducer.The proposed MEMS gravimeter has performed the co-site earth tides measurement with a commercial superconducting gravimeter GWR iGrav with the results showing a correlation coefficient of 0.91.
基金supported by the Natural Science Foundation of Guangdong Province (No. 2021A1515010198)the Guangzhou Science and Technology Plan Project (No. 202102020794)the National Key R&D Program of China (No. 2020YFC2200500)
文摘In this paper,we present a suppression method for the thermal drift of an ultra-stable laser interferometer.The detailed analysis on the Michelson interferometer indicates that the change in optical path length induced by temperature variation can be effectively reduced by choosing proper thickness and/or incident angle of a compensator.Taking the optical bench of the Laser Interferometer Space Antenna Pathfinder as an example,we analyze the optical bench model with a compensator and show that the temperature coefficient of this laser interferometer can be reduced down to 1 pm/K with an incident angle of 0.267828 rad.The method presented in this paper can be used in the design of ultra-stable laser interferometers,especially for space-based gravitational waves detection.
