Off-axis digital holographic microscopy: practical design parameters for operating at diffraction limit.

Area of Science:

• Optical Microscopy
• Holography
• Image Processing

Background:

• Digital holographic microscopy (DHM) presents unique challenges when using microscope objectives (MOs) not found in conventional microscopy.
• Phase curvature is a known artifact in DHM, impacting quantitative phase imaging and leading to developed mitigation strategies.
• Less obvious conditions related to MOs in DHM affect diffraction-limited operation, even for amplitude or intensity imaging.

Purpose of the Study:

• To thoroughly analyze the physical parameters governing the appropriate use of MOs in DHM.
• To establish criteria for achieving diffraction-limited performance in DHM systems using MOs.
• To provide a theoretical framework and validation for MO utilization in DHM.

Main Methods:

• Theoretical modeling of a regular DHM system based on imaging theory.
• Analysis of the hologram's Fourier spectrum to assess DHM performance.
• Derivation of criteria for diffraction-limited DHM operation considering microscope and recording parameters.

Main Results:

• Identification of key physical parameters influencing MO performance in DHM.
• Development of criteria for optimizing MOs in DHM for diffraction-limited imaging.
• Validation of theoretical findings through numerical modeling and experimental results.

Conclusions:

• Appropriate MO selection and parameter tuning are crucial for diffraction-limited DHM.
• The derived criteria enable enhanced performance in DHM for both phase and amplitude/intensity imaging.
• This work provides a foundation for optimizing MO usage in DHM systems.