A Portable DIY Speckle Interferometer for Evaluating 3D Deformation Fields

The paper presents a Do It Yourself speckle interferometer for evaluating 3D deformation fields. The interferometer was designed and realized with the aim of obtaining a low-cost and portable device for measuring deformations on small areas. The costs were reduced chiefly thanks to the light sources, the PZT actuator and the control electronics used for realizing the device. In particular the illumination was obtained by means of three laser diodes, emitting 50 mW at 660 nm, and the phase-shifter is a piezoelectric actuator designed, realized and calibrated by the authors in previous work. Finally by the control electronics, designed on purpose for the present application and interfaced with a laptop by a serial port, it is possible to control accurately the light intensity or each diode and the position of the PZT actuator.