Fiber-Coupled Common-Path Shearography for Simultaneous Measurement of Surface Deformation and Slope

A mechanical quantity sensing framework is proposed, which is based on fiber-coupled common-path shearography, for the simultaneous measurement of deformation and slope. An optical fiber directs the reference wave into the system for the generation of holograms without breaking the common-path structure. The present shearography possesses three features for mechanical quantity sensing, namely, the zero-approaching shear amount, the separate control of spatial carriers, and the scrambled reference wave. Single-shot phase measurement scheme is implemented by the spatial carrier method, in which the deformation and slope are retrieved from a single frame of interference pattern. Fiber scrambling is brought into the system to flatten the intensity distribution of the fiber-directed reference field and deliver a quality-enhanced phase map. Physical principle is demonstrated. Preliminary experiments are carried out to verify the feasibility and functionality of the proposed framework.

Automated summary

Proposal of a mechanical quantity sensing framework based on fiber-coupled common-path shearography for simultaneous measurement of deformation and slope. Optical fiber is used to generate holograms without breaking the common-path structure. Features include zero-approaching shear amount, separate control of spatial carriers, and scrambled reference wave. Single-shot phase measurement scheme is implemented by the spatial carrier method. Fiber scrambling is used to enhance the phase map quality. Physical principle demonstrated, and preliminary experiments verify the feasibility and functionality of the framework.