Dynamical measurement of refractive index distribution using digital holographic interferometry based on total...

Area of Science:

• Optics and Photonics
• Materials Science
• Chemical Engineering

Background:

• Accurate refractive index measurement is crucial for material characterization and process monitoring.
• Existing methods may lack dynamic range or real-time capabilities for complex media.

Purpose of the Study:

• To develop a dynamic method for measuring refractive index distribution over a large range.
• To enable real-time monitoring of index variations in liquids and solids.

Main Methods:

• Combining digital holographic interferometry with total internal reflection.
• Recording holograms of liquids on a prism surface during diffusion using CCD.
• Reconstructing phase shift differences using double-exposure holographic interferometry.

Main Results:

• Two-dimensional refractive index distributions were directly calculated from phase shift differences.
• The method successfully measured index variations in mixed liquids.
• The technique demonstrated potential for solid media and chemical reaction monitoring.

Conclusions:

• The proposed method offers a robust approach for dynamic refractive index measurement.
• This technique is versatile, applicable to liquids, solids, and chemical processes.
• It provides valuable insights into diffusion and reaction dynamics.