Some discussion on high-speed-imaging-based optical coherent measurement

Optical coherent detection is a precise and non-contact method for measurement of tiny deformation or movement of an object. In the last century, it can only be used on the static or quasi-static measurement of deformation between two statuses. Recently it has been applied on dynamic measurement with the help of high-speed camera. The advantage of this technique is that it can offer a full-field measurement. However, due to the limited capturing rate of high-speed camera, its capability in temporal domain cannot meet the requirements of many applications. In this study, several issues in high-speed-camera-based optical interferometry are discussed. For example, introduction of carrier in temporal and spatial domain, signal processing in temporal-frequency domain, and the introduction of dual-wavelength interferometry in dynamic measurement. The discussion leads to a clue to select suitable technique to fulfill whole-field dynamic measurement at different ranges.