Evaluation Of Systematic Error Induced By Raman Laser Frequency And Inclination For Atom Gravimeters

High-precision absolute gravity measurement has important applications for inertial navigation,resource exploration,and fundamental physics research.Atom interferometry gravimeter is one of the important means to implement the measurement.In order to meet the requirements of in-situ gravity measurement and absolute graivimeter comparison,atom interferometry gravimeters are gradually developed from the laboratory research stage to mobile and compact set-up.Based on the breakthrough of our previous laboratory platform aparatus,my Ph.D program is on a transportable atom gravimeter?TAG?.And my work mainly includes the following three aspects:1.Optimising the design and development of TAG's electronic system.Aiming at the mobilbilty demand,we independently designed and tested the voltage source,current source,optical power feedback,etc.,and combined with customized RF and microwave devices to realize the miniaturization and modularization of the electronic system;In the mean time,a microwave repump method has been implemented to help with the atom final state detection.2.Raman laser frequency related error evaluation.Based on frequency stabilization and optical phase-locked loop,the system errors introduced from the 10 MHz frequency standard,nonlinearty of the RF signal source and the phase-locked loop during the Raman effective frequency chirping process were evaluated.A scheme for in-situ calibration of the 10 MHz frequency standard using the atomic gravimeter itself has been proposed and implemented.And the corresponidng uncertainty had been evaluated on the order of 0.1 ?Gal.3.Raman laser beam inclination related systematic error evaluation.The earth rotation will induce Coriolis effect,and the approach of rotating the Raman laser direction is utilized to compensate and evaluate the Coriolis effect for the atom interferometry gravimeter.On the other hand,the inclination of the Raman laser direction from the vertical direction is an prominant systematic error source.An optical approach for rapid measurement of this inclination has been proposed and developed.Finally,these two Raman laser inclination related errors had been evaluated on the order of ?Gal.Based on the work mentioned above,the sensitivity of our developed TAG achieves 43?Gal/Hz^1/2 level,and the uncertainty is 3?Gal.The instrument has had participated in the 10 th International Comparison of Absolute Gravimeter?ICAG?,which had proved the performance of the apparatus.This work paved the road for rapid in-situ measurements by atom interferometry gravimeter.