Trimodal imaging system capable of quantitative phase imaging without 2 pi ambiguities

Area of Science:

• Optical Physics
• Nanotechnology
• Microscopy

Background:

• Interferometric phase imaging is crucial for analyzing transparent materials.
• Phase ambiguities (2 pi jumps) limit the accuracy of traditional methods.
• Pseudoheterodyne Mach-Zehnder interferometers offer potential for phase measurement.

Purpose of the Study:

• To develop a novel interferometric phase imaging technique.
• To eliminate 2 pi phase ambiguities in phase imaging.
• To enable high-resolution imaging of translucent samples.

Main Methods:

• Utilized an actively controlled angular displacement glass plate in the reference arm.
• Employed a pseudoheterodyne Mach-Zehnder interferometer stabilized against environmental disturbances.
• Raster scanned phase objects in the sample arm while maintaining constant output phase.

Main Results:

• Achieved unwrapped phase images of translucent samples without phase ambiguities.
• Successfully imaged samples with thicknesses ranging from 150 nm to 1.5 micrometers.
• Integrated the system into a near-field scanning optical microscope for multi-modal analysis.

Conclusions:

• The developed technique effectively resolves 2 pi phase ambiguities in interferometric imaging.
• This method allows for precise phase imaging of thin translucent specimens.
• The integration with near-field scanning optical microscopy enables comprehensive sample characterization.