Dynamically measuring unstable reaction–diffusion process by using digital holographic interferometry

• We present a method for dynamically and quantitatively investigating the unstable reaction–diffusion process by using digital holographic interferometry.
• The analytical method of hologram based on unstable diffusion is used.
• The experimental setup is simplified because the optical fiber device is used.

We present a method for dynamically and quantitatively investigating the unstable reaction–diffusion process by using digital holographic interferometry. Taking substitution reaction with flat aluminum in copper sulfate solution as a sample, the reaction rate and concentration variation are quantitatively measured by numerically reconstructing a series of phase change maps reflecting the refractive index distribution and variation trend of the solution during the reaction–diffusion process. In addition, the measurement accuracy of concentration and the size resolution are analyzed. The experiment results certify the feasibility and validity of the presented method in the full-field, dynamical and quantitative measurement of unstable reaction–diffusion processes.