By analyzing the direct frequency modulation and optical feedback effect of laser diode, a theoretical model for measuring small vibration displacement and velocity is discussed.
分析了在直接频率调制下,激光二极管中的光反馈效应,探讨了振动微小位移和速度的理论模型。
2
ESPI can measure the object, through forming a carrier pattern on the object surface (carrier pattern modulation), analyze the relation between displacement field and altitude of the object surface.