【摘要】 提出了一种用于绝对距离测量的光纤超外差干涉系统，简述了该方案的原理，给出了信号处理的框图，并进行了初步实验。对系统的误差分析表明，在光强较弱、信噪比差的情况下，光学元件的非理想特性以及测量信号与参考信号之间的耦合是引起测量误差的主要原因。更多还原

【Abstract】 A fiber optical super heterodyne absolute distance interferometer (ADI) is proposed. The principle of the ADI is briefly reviewed with the signal processing method presented. Experiment shows that the system can not be used in practice without the improvement of photo detector’s signal to noise ratio (SNR). The property of the optical elements and signal coupling between the measurement and reference respond for the main errors.更多还原