Parallel-quadrature phase-shifting digital holographic microscopy using polarization beam splitter

Area of Science:

• Optics and Photonics
• Microscopy Techniques
• Digital Holography

Background:

• Traditional digital holography often suffers from phase errors due to mechanical vibrations and air turbulence.
• Off-axis recording geometry in conventional methods limits the spatial filter dimension, impacting reconstruction quality.

Purpose of the Study:

• To develop a digital holography microscopy technique that overcomes limitations of traditional methods.
• To improve the accuracy and capability of holographic reconstructions by eliminating phase errors and enhancing spatial filtering.

Main Methods:

• A parallel-quadrature phase-shifting method was employed, recording two π/2 phase-shifted holograms simultaneously.
• Polarization phase-shifting, a slightly off-axis geometry, and two CCD sensors were utilized.
• Circularly polarized object beam and a 45° polarized reference beam were combined via a polarizing beam splitter for parallel phase-shifting.

Main Results:

• Simultaneous hologram recording effectively eliminated phase errors caused by environmental disturbances.
• The DC term was successfully removed by subtracting the two recorded holograms.
• Both amplitude and phase information of objects were reconstructed with improved capability.

Conclusions:

• The presented digital holography microscopy technique offers superior reconstruction capability compared to traditional off-axis holography.
• Simultaneous recording and the specific geometry significantly enhance robustness against environmental noise.
• This method provides a more effective approach for high-fidelity holographic reconstruction.