Power stability of different lasers and its effect on the outcome of phase-stepping shearography experiments

We examined the effect and influence of power stability of different commonly used lasers on the outcome of phase-stepping shearographic experiments. We performed power stability measurements with three different lasers (helium-neon laser, red diode laser and green frequency-doubled neodymium laser). We subsequently performed phase-stepping shearography experiments using these lasers as light sources. We found a correlation with the quality of the shearograms and the power stability of the lasers. This enables us to compare the suitability of various lasers for phase-stepping shearography experiments and to choose the best laser for this application.