High synchronization absolute distance measurement using a heterodyne and superheterodyne combined interferometer

【摘要】 We propose an absolute distance measurement method that employs heterodyne and superheterodyne combined interferometers to achieve synchronous detection and demodulation of multiwavelengths. Coarse and fine synthetic wavelengths are generated by a dual-longitudinal-mode He–Ne laser and four acoustic optical frequency shifters. Further,to improve phase synchronization measurement for multiwavelengths, we analyze the demodulation characteristics of coarse and fine measurement signals and adopt a demodulation method suitable for both signals. Experimental results demonstrate that the proposed method can achieve high-precision synchronous demodulation of multiwavelengths, and standard deviation is 1.7 × 10^-5m in a range of 2 m.更多还原

【Abstract】 We propose an absolute distance measurement method that employs heterodyne and superheterodyne combined interferometers to achieve synchronous detection and demodulation of multiwavelengths. Coarse and fine synthetic wavelengths are generated by a dual-longitudinal-mode He–Ne laser and four acoustic optical frequency shifters. Further,to improve phase synchronization measurement for multiwavelengths, we analyze the demodulation characteristics of coarse and fine measurement signals and adopt a demodulation method suitable for both signals. Experimental results demonstrate that the proposed method can achieve high-precision synchronous demodulation of multiwavelengths, and standard deviation is 1.7 × 10^-5m in a range of 2 m.更多还原