Widefield lensless imaging through a fiber bundle via speckle correlations

Area of Science:

• Optics and Photonics
• Biomedical Imaging
• Materials Science

Background:

• Flexible fiber-optic endoscopes enable deep imaging but face miniaturization and performance limits.
• Existing lensless methods using wavefront shaping are sensitive to fiber bending.
• Distal end focusing/scanning mechanisms hinder endoscope miniaturization and speed.

Purpose of the Study:

• To develop a bend-insensitive, lensless imaging approach for fiber bundles.
• To overcome the limitations of distal end components in conventional endoscopes.
• To enable high-resolution imaging in miniaturized endoscopic devices.

Main Methods:

• A novel lensless imaging approach utilizing speckle correlations in fiber bundles.
• Single-shot image acquisition analyzing a single camera frame.
• Computational image retrieval exploiting inherent phase information preserved during fiber propagation.

Main Results:

• Demonstrated a bend-insensitive imaging capability.
• Achieved imaging of planar objects at variable working distances.
• Produced unpixelated, diffraction-limited images with miniaturization limited only by fiber diameter.

Conclusions:

• The proposed speckle-correlation method offers a robust, lensless solution for fiber-based imaging.
• This technique eliminates the need for distal end focusing/scanning mechanisms.
• It paves the way for highly miniaturized, high-performance endoscopic imaging systems.