Single-pixel microscopy with enhanced lateral resolution

Area of Science:

• Optics and Photonics
• Biomedical Imaging
• Microscopy

Background:

• Optical microscopy faces limitations due to the diffraction limit, restricting spatial resolution.
• Structured Illumination Microscopy (SIM) enhances resolution but hasn't been integrated with Single-Pixel Microscopy (SPM).

Purpose of the Study:

• To introduce a super-resolution SPM (SR-SPM) by merging SIM principles with SPM.
• To develop novel structured sampling patterns (SSPs) for enhanced resolution in SPM.

Main Methods:

• Developed novel SSPs combining Walsh-Hadamard and fringe patterns with phase shifts and orientations.
• Projected SSPs using a digital micromirror device (DMD) and captured sequential measurements with a single-pixel detector.
• Reconstructed images using single-pixel imaging (SPI) and SIM algorithms for resolution enhancement.

Main Results:

• Achieved a significant resolution improvement, increasing the MTF spatial frequency limit from 1000 to 1500 lp/mm.
• Demonstrated enhanced resolution and finer feature differentiation in brightfield and fluorescence imaging of biological samples.
• Validated the system with quantum-dot-labelled epithelial cells and fluorescent microspheres.

Conclusions:

• The proposed SR-SPM system offers a cost-effective and efficient method for achieving enhanced resolution.
• This technique paves the way for broader applications of single-pixel imaging in complex environments.
• SR-SPM overcomes diffraction limits for improved biomedical and engineering imaging.