Optical Fiber Superheterodyne Interferometer with two wavelengths HeNe Laser for Absolute Distance Interferometry

摘要

The paper proposes an Absolute Distance Interferometry(ADI) system using the technique of heterodyne and superheterodyne detecting. A two wavelengths HeNe 633nm Laser is employed to generate a long synthetic wavelength for measuring absolute distance. The characteristics of the heterodyne ADI system using AOMs are analyzed. The optical wave cross talk and poor wave front quality will decreas the performence of the heterodyne ADI system. By using the technique of superheterodyne and optical fiber, the perdormence of the new ADI system is improved. The common optical path and reference signal picking configuration in the interferometer eliminate the affection of air turbulence and problem from optical fiber effectively.