Holographic interferometry with multiple wavelengths

Area of Science:

• Optics and Photonics
• Interferometry
• Holography

Background:

• Holographic interferometry is a technique used to measure small displacements.
• Identifying zeroth-order fringes, indicating zero displacement, is challenging when locations are unknown.

Purpose of the Study:

• To provide a straightforward method for identifying zeroth-order fringes in holographic interferometry.
• To address the unsolved problem of locating zero displacement fringes.

Main Methods:

• Recording double-exposure holograms of objects.
• Utilizing full-color holography with three or more wavelengths.
• Observing fringe color for identification.

Main Results:

• Zeroth-order fringes are distinctly identified by their white color.
• This method simplifies fringe analysis in holographic interferometry.
• Successful identification of zero displacement fringes is achieved.

Conclusions:

• The proposed method offers a simple and effective solution for identifying zeroth-order fringes.
• Full-color, multi-wavelength holography enhances the practical application of holographic interferometry.
• This technique resolves a key challenge in measuring displacements using holography.