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Abstract Quantitative phase imaging (QPI) recovers the exact wavefront of light from intensity measurements. Topographical and optical density maps of translucent microscopic bodies can be extracted from these quantified phase shifts. We demonstrate quantitative phase imaging at the tip of a coherent fiber bundle using chromatic aberrations inherent in a silicon nitride hyperboloid metalens. Our method leverages spectral multiplexing to recover phase from multiple defocus planes in a single capture using a color camera. Our 0.5 mm aperture metalens shows robust quantitative phase imaging capability with a$${28}^{\circ}$$ field of view and 0.$${2}{\pi}$$ phase resolution ( ~ 0.$${1}{\lambda}$$ in air) for experiments with an endoscopic fiber bundle. Since the spectral functionality is encoded directly in the imaging lens, the metalens acts both as a focusing element and a spectral filter. The use of a simple computational backend will enable real-time operation. Key limitations in the adoption of phase imaging methods for endoscopy such as multiple acquisition, interferometric alignment or mechanical scanning are completely mitigated in the reported metalens based QPI.
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Near-infrared metalens for high-resolution and deep focus optical coherence tomography
High-resolution endoscopic optical imaging is a crucial technique in biological imaging to examine the inside organs. There is a trade-off between lateral resolution and depth of focus in such applications. Traditional Optical Coherence Tomography provides an increased depth range but falls short of desired resolution. The combination of both higher resolution and larger imaging depth of focus of metalens can improve the clinical utility of endoscopic optical imaging. In this work, we designed, analyzed, and fabricated a 500 µm diameter metalens operating at 1300 nm to achieve high resolution and large imaging depth of focus, therefore, addressing this need. The full width at half maximum and depth of focus for the proposed metalens are 3.10 and 286 µm, respectively.
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- Award ID(s):
- 2132929
- PAR ID:
- 10597156
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- AIP Advances
- Volume:
- 12
- Issue:
- 12
- ISSN:
- 2158-3226
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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