外差激光探针的拍频与相位差

BEAT FREQUENCY AND PHASE DIFFERENCE OF HETERODYNE LASER PROBE

本文详细推导了用振幅调制激光为光源外差激光探针的信号光与参考光干涉光强表达式。通过分析其中光学项与调制包络项的相位因子指出了相位中拍频与相位差随时间变化的同一性。从而在理论上统一了光拍频与传统的干涉现象,这一结果对拍频为常量与拍频随时间变化两种情况均适用,由此可以给出用外差激光探针测振动的理论依据。

In the paper. the interference intensity of signal laser beam and the reference one is carried out in detail on a heterodyne laser probe with amplitude modulated laser source. Analized the optical phase and the envelope phase, the consistency of beat frequency and variation of phase difference is presented. The theoretical equality of optical beat frequency and traditional interference phenomenon is performed, the result can be applied to varing beat frequency as well as to constant beat frequency, which provid a theoretical basis for detection of vibration using heterodyne laser probe.