Simultaneous dual-wavelength off-axis flipping digital holography.

Area of Science:

• Optics and Photonics
• Biomedical Imaging
• Materials Science

Background:

• Quantitative phase imaging (QPI) is crucial for label-free microscopy.
• Traditional QPI methods often require complex setups or multiple measurements.
• Developing faster and simpler QPI techniques is essential for broader applications.

Purpose of the Study:

• To develop a simplified two-wavelength off-axis digital holography system for QPI.
• To achieve quantitative phase and thickness measurements from a single interferogram.
• To demonstrate a robust and easily alignable holographic setup.

Main Methods:

• Implemented a two-wavelength off-axis digital holography setup.
• Utilized beam flipping for interference and polarization modulation for spatial multiplexing.
• Employed a single-shot interferogram acquisition on a CCD camera.
• Developed algorithms for extracting two-wavelength unwrapped phase and thickness information.

Main Results:

• Successfully extracted phase and thickness information from a single interferogram.
• Demonstrated the technique's capability with a step target and circular pillar.
• Achieved straightforward alignment without requiring pinholes, gratings, or dichroic mirrors.

Conclusions:

• The developed two-wavelength digital holography system offers efficient and simplified QPI.
• Single-shot acquisition and straightforward alignment make the technique practical for various applications.
• This method advances label-free imaging by providing rapid and accurate phase and thickness measurements.