Enhanced Quantitative Wavefront Imaging for Nano-Object Characterization

Area of Science:

• Optical physics
• Nanotechnology
• Metrology

Background:

• Quantitative phase imaging (QPI) offers label-free nano-object characterization.
• Current common path QPI lacks sufficient phase sensitivity for precise single-shot measurements of nanoparticles, viruses, and vesicles.
• Existing methods struggle with accurate mass and polarizability estimations.

Purpose of the Study:

• To adapt Zernike filtering for wavefront imaging to enhance phase sensitivity in QPI.
• To develop a method for precise nano-object detection and metrology.
• To improve the quantitative retrieval of both intensity and phase information.

Main Methods:

• Revisiting Zernike filtering principles for wavefront imaging applications.
• Implementing a Fourier-plane add-on to existing wavefront sensing setups.
• Conducting numerical simulations and experimental validation using high-resolution wavefront sensing.

Main Results:

• Achieved over an order of magnitude increase (×12) in phase sensitivity for subdiffraction objects.
• Demonstrated significant enhancement of phase sensitivity compared to existing common path implementations.
• Enabled quantitative retrieval of both intensity and phase information for nano-objects.

Conclusions:

• The proposed Fourier-plane add-on significantly improves phase sensitivity in QPI.
• This advancement enables more precise nano-object detection and metrology.
• The method is adaptable for various nano-objects like vesicles, viruses, and nanoparticles.