Short-exposure annular LED array-based digital refocusing microscopy via multiplexed illumination

Area of Science:

• Microscopy
• Optical Imaging
• Biophysics

Background:

• Digital refocusing microscopy (DRM) extends microscope depth of field without mechanical scanning.
• Sequential image acquisition in LED-array DRM limits temporal resolution.
• Short-exposure imaging can cause low contrast and loss of detail.

Purpose of the Study:

• To improve the temporal resolution of LED-array-based DRM.
• To maintain high image quality under short-exposure conditions.
• To reduce measurement requirements for faster imaging.

Main Methods:

• Developed short-exposure DRM using multiplexed illumination.
• Introduced an annular LED array configuration for DRM.
• Reduced measurements from 37 to 16 compared to full circular arrays.

Main Results:

• Achieved higher imaging speed while preserving digital refocusing image quality.
• Enhanced image contrast and spatial resolution with the annular LED array.
• Improved SSIM in dark regions by at least 3.16 times compared to sequential single-LED illumination.

Conclusions:

• The proposed strategies create a practical framework for high-speed DRM.
• The method enables dynamic observation of biological samples.
• Optimized LED illumination strategies significantly improve DRM performance.