Single-shot slightly off-axis digital holographic microscopy with add-on module based on beamsplitter cube

Area of Science:

• Optical microscopy
• Quantitative Phase Imaging (QPI)
• Holography

Background:

• Slightly off-axis digital holographic microscopy (SO-DHM) is a novel technique for QPI.
• It offers advantages over traditional on-axis and off-axis interferometric methods.
• Existing SO-DHM configurations have limitations in speed or field of view.

Purpose of the Study:

• To develop a single-shot SO-DHM approach using an add-on module for regular microscopes.
• To enable enhanced quality complex amplitude retrieval for QPI.
• To facilitate the analysis of fast-dynamic events and optimize imaging system usage.

Main Methods:

• An add-on module with a beamsplitter (BS) cube interferometer and Stokes lens (SL) was adapted to a standard microscope.
• The module simultaneously records two phase-shifted holograms (π radians apart) in a single snapshot.
• Numerical processing of the two holograms retrieves the complex amplitude distribution.

Main Results:

• The single-shot SO-DHM approach successfully retrieved complex amplitude with enhanced quality.
• The method allows for the analysis of fast-dynamic events due to its single-shot capability.
• Experimental validation was performed on various samples using an Olympus BX-60 microscope.

Conclusions:

• The proposed SO-DHM approach optimizes the space-bandwidth product compared to off-axis configurations.
• It is easily implementable in conventional microscopes, upgrading them for QPI.
• This method provides a valuable tool for high-quality, real-time phase imaging.