A Robust All-Fiber Push-Pull-Type Displacement Interferometer for Dynamic Deformation Experiments

A robust all-fiber push-pull-type displacement interferometer has been developed for dynamic deformation experiments and is described in this paper. This instrument includes a 90° optical hybrid module used to complement orthogonal coding of its fringe patterns. Hence, phase variation resulted by target displacement can be resolved point-by-point with the quadrature signals. The push-pull mode similar to the conventional VISAR (velocity interferometer system for any reflector) allows doubling output signals and cancelling noise. It has been successfully validated in gas-gun plate-impact experiments and issues in the data reduction procedure are discussed.