Transmission and total internal reflection integrated digital holographic microscopy

Area of Science:

• Optical microscopy
• Holography
• Metrology

Background:

• Digital holographic microscopy (DHM) is a powerful technique for quantitative phase imaging.
• Measuring both refractive index and thickness profiles of samples is crucial in material science and biology.
• Existing methods often require multiple setups or are destructive.

Purpose of the Study:

• To develop an integrated microscopy system combining transmission and total internal reflection (TIR) DHM.
• To enable simultaneous, nondestructive measurement of 2D refractive index distribution and thickness profile.
• To characterize transparent or semi-transparent liquid and solid samples.

Main Methods:

• Integration of a custom Dove prism into a DHM setup.
• Utilizing angular and polarization multiplexing for TIR-DHM.
• Employing transmission DHM for phase information extraction.
• Nondestructive and dynamic measurement capabilities.

Main Results:

• Successfully determined the 2D refractive index distribution of a specimen using TIR-DHM.
• Unambiguously calculated the thickness profile from phase information using transmission DHM.
• Demonstrated simultaneous measurement of both parameters.

Conclusions:

• The developed integrated TIR-DHM and transmission DHM is a versatile, nondestructive tool.
• This technique allows for simultaneous characterization of refractive index and thickness.
• It offers a novel approach for analyzing transparent and semi-transparent materials.