Quantitative phase imaging endoscopy with a metalens.

Area of Science:

• Optical imaging
• Microscopy
• Biophotonics

Background:

• Quantitative phase imaging (QPI) reconstructs light wavefronts from intensity data.
• QPI enables topographical and optical density mapping of translucent samples.
• Traditional QPI methods face challenges in endoscopic applications, including complex alignment and mechanical scanning.

Purpose of the Study:

• To demonstrate quantitative phase imaging at the tip of a coherent fiber bundle.
• To overcome limitations of current endoscopic phase imaging techniques.
• To develop a compact and simplified QPI system for endoscopic use.

Main Methods:

• Utilized a silicon nitride hyperboloid metalens with inherent chromatic aberrations.
• Employed spectral multiplexing to recover phase information from multiple defocus planes in a single camera capture.
• Integrated the metalens as both a focusing element and spectral filter for a 0.5 mm aperture system.

Main Results:

• Achieved robust quantitative phase imaging with a $$ field of view and 0. $$ phase resolution (approx. 0. $$ in air).
• Demonstrated QPI capability with an endoscopic fiber bundle.
• The metalens-based system mitigated the need for multiple acquisitions, interferometric alignment, or mechanical scanning.

Conclusions:

• A metalens-based quantitative phase imaging system is feasible for endoscopic applications.
• The developed method simplifies QPI by leveraging inherent chromatic aberrations and spectral multiplexing.
• The system's design enables real-time operation with a simple computational backend, paving the way for advanced endoscopic imaging.