Phase-shifting Zernike phase contrast microscopy for quantitative phase measurement

Area of Science:

• Optics and Photonics
• Microscopy Techniques
• Image Processing

Background:

• Zernike phase contrast microscopy is a vital tool for visualizing transparent specimens.
• Traditional methods often suffer from artifacts like halo and shade-off effects.
• Quantitative phase measurement requires precise control over phase shifts.

Purpose of the Study:

• To develop an enhanced Zernike phase contrast microscopy method for quantitative phase measurements.
• To integrate a phase-shifting mechanism with improved illumination for higher accuracy.
• To minimize common artifacts and noise in phase contrast imaging.

Main Methods:

• Utilized a ring of discrete point light sources for illumination.
• Implemented a phase-shifting mechanism using a rotating silica plate for phase retardation.
• Applied three distinct phase steps to the undiffracted light component.
• Developed a quantitative evaluation method for phase specimens.

Main Results:

• Achieved quantitative phase measurements of microscopic objects.
• Significantly reduced halo and shade-off effects.
• Lowered coherent noise levels.
• Attained high lateral resolution through the improved illumination scheme.

Conclusions:

• The proposed method offers a robust approach for quantitative phase imaging.
• This technique overcomes limitations of conventional phase contrast microscopy.
• It provides high-quality phase measurements with enhanced resolution and reduced artifacts.