Super-resolved multispectral lensless microscopy via angle-tilted, wavelength-multiplexed ptychographic modulation.

Area of Science:

• Optics and Photonics
• Microscopy
• Biomedical Imaging

Background:

• Lensless microscopy offers miniaturization and cost-effectiveness.
• Multispectral imaging provides rich functional and structural information.
• Ptychography enables high-resolution phase retrieval but faces challenges in multiplexed spectral reconstruction.

Purpose of the Study:

• To develop an angle-tilted, wavelength-multiplexed ptychographic approach for lensless on-chip multispectral microscopy.
• To overcome spectral ambiguities in ptychographic reconstruction.
• To achieve high-resolution quantitative multispectral imaging for applications like digital pathology.

Main Methods:

• Simultaneous illumination of the specimen with five wavelengths.
• Utilizing a prism for spectral dispersion, creating angle-tilted illumination.
• Employing a diffuser for spectral information encoding in 2D intensity measurements.
• Integrating an up-sampling procedure in the reconstruction process to enhance resolution.

Main Results:

• Successfully reconstructed five complex object profiles at different wavelengths.
• Achieved a half-pitch resolution of 0.55 µm with a 1.85 µm pixel size image sensor.
• Demonstrated quantitative and high-quality multispectral reconstructions of stained tissue sections.

Conclusions:

• The developed method enables high-resolution, label-free multispectral imaging on a chip.
• The angle-tilted, wavelength-multiplexed ptychographic approach effectively resolves spectral ambiguities.
• This technique shows significant potential for advancing digital pathology and other biomedical imaging fields.