Structured illumination microscopy with partially coherent illumination for phase and fluorescent imaging

Area of Science:

• Microscopy and Imaging Technologies
• Optical Physics
• Biomedical Optics

Background:

• Traditional microscopy techniques often face limitations in achieving both high resolution and quantitative phase contrast simultaneously.
• Speckle noise in coherent imaging systems can degrade image quality and hinder accurate analysis.
• Developing dual-modality imaging systems offers a pathway to comprehensive sample characterization.

Purpose of the Study:

• To develop and demonstrate a novel partially coherent illumination based (PCI-based) Super-resolution Intensity Modulation (SIM) apparatus.
• To enable simultaneous label-free quantitative phase imaging and super-resolved/sectioned fluorescence imaging of the same sample.
• To showcase the system's capability in suppressing speckle noise and providing enhanced sectioning for improved image quality.

Main Methods:

• Generation of partially coherent illumination (PCI) by using a rotating diffuser on a monochromatic laser beam.
• Implementation of a dual-modality imaging system capable of acquiring both phase and fluorescence data.
• Application of the system to image various samples, including transparent cells, fluorescent beads, and biological tissues.

Main Results:

• Achieved label-free quantitative phase images of transparent cells with high endogenous contrast and superior sectioning capability.
• Obtained super-resolved and optically sectioned fluorescence images of diverse specimens like fluorescent beads, rat tail crosscut, wheat anther, and hibiscus pollen.
• Demonstrated significant suppression of speckle noise, leading to improved image clarity and quantitative accuracy.

Conclusions:

• The developed PCI-based SIM apparatus offers a powerful dual-modality imaging solution for microscopy.
• The system provides simultaneous high-quality phase and fluorescence imaging, overcoming limitations of conventional methods.
• This technology holds significant potential for applications across biomedical, industrial, and chemical fields requiring detailed sample analysis.