Research On Synthetic-wave Absolute-distance Heterodyne Interferometric Techniques Using Dual-Frequency Solid State Laser

Synthetic-wave absolute-distance interferometry is kind of no-guideway measurement,which has become one of the most important research directions in the field of measurement today.Its research goal is to achieve large-scale and high-precision absolute distance measurement.The synthetic-wave interferometry measurement technology has advantages such as optical path breaking prevention and no-guideway during measurement,so it has broad application prospects.Therefore,it is of great significance to conduct research on the absolutedistance measurement technology of synthetic-wavelength interferometry.In this thesis,a synthetic-wave absolute-distance heterodyne interferometric measurement system has been designed and experimented,in which the light source is the quadrature demodulation Pound-Drever-Hall(QD-PDH)frequency-stabilized LD-pumped two-cavity dualfrequency Nd:YAG laser(TCDFL)at 1064nm.The research content of this thesis mainly includes the following aspects:Firstly,the current research status of absolute-distance measurement techniques in recent years has been reviewed,and commonly used laser interferometer structures have been briefly introduced.The principle of synthetic-wave absolute-distance interferometric measurement has been analyzed.Secondly,using a QD-PDH stabilized LD pumped 1064nm two-cavity dual-frequency Nd:YAG laser as the light source,a research scheme for a synthetic-wave absolute-distance heterodyne interferometric measurement system by employing the structure of Mach-Zehnder interferometer has been designed.The variation law of the interference signal in this scheme have been simulated and studied,and the feasibility of this scheme has been analyzed.Thirdly,a signal conditioning circuit for synthetic-wave absolute-distance heterodyne interferometric measurement has been designed,including hardware schematic diagrams of filtering circuit,amplification circuit,and power circuit.The corresponding conditioning circuit modules have been simulated and verified,and a PCB has been designed and manufactured,and experimental verification has been conducted.Finally,an experimental system for TCDFL synthetic-wave absolute-distance heterodyne interferometric measurement has been established,and the calibration method and absolutedistance interferometric measurement technology of the 24GHz frequency-difference TCDFL synthetic-wavelength have been experimentally studied;The research results indicate that the calibration value of the synthetic-wavelength in the air under the environment is 12.4614mm.When the absolute-distances measured are 500mm,900mm,absolute-distance measurement uncertainty of 10-6 order has been obtained,achieving precise absolute-distance measurement.In summary,the research scheme of the TCDFL synthetic-wave absolute-distance heterodyne interferometric measurement system designed in this thesis is feasible and can meet the needs of high-precision absolute distance measurement,laying a solid foundation for further research and development of synthetic-wave absolute-distance interferometric measurement instruments in the future.