Simultaneous 3D measurement for infrared chips with speckle interferometry

• A compact device that is able to simultaneously measure full-field three dimensional deformation of an object has been developed. • A real-time computing scheme enabling quantitative characterization of 3D deformation is proposed. • The 3D deformation of the infrared sensor due to variations of temperature is characterized. • The precision and robustness of the developed techniques have been validated via experiments and simulations. Temperature-induced deformation in the infrared detector chip is a key index for evaluating image aberration and stress concentration. Development of an evaluation means for simultaneous characterization of 3D deformation is of great interest to engineering societies. In this study, an integrated device based on speckle interferometry has been developed for evaluation of the three-dimensional (3D) deformation of the infrared detector chip with variations of temperature. With the use of a 3CCD color camera and a group of optical fibers, the 3D displacement components of the detector surface are measured simultaneously during the cooling process. A temporal phase shifting scheme based on GPU parallel computing has been proposed to enable quantitatively real-time 3D measurement in three image layers at a rate of 20 fps. The integrated device has been validated with a benchmark test. The experimental results show a good agreement with the theoretical solution validating the stability and accuracy of the experimental device. The developed speckle interferometry device provides an accurate means in simultaneously evaluating the 3D deformation of the infrared detector chip due to temperature variations.