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Metasurface integrated optics for fluorescence imaging endoscopy
Optics Express
|June 11, 2026
Summary
A novel metasurface integrated with a gradient refractive index (GRIN) lens enhances confocal fluorescence imaging quality. This hybrid system simplifies optics, improving contrast and resolution in endoscopy without explicit chromatic aberration correction.
Area of Science:
- Optics
- Biomedical Engineering
- Materials Science
Background:
- Metasurfaces offer off-axis aberration correction in reflectance imaging.
- Chromatic aberration limits image quality in confocal fluorescence imaging.
- Conventional color correction uses complex multi-lens systems.
Purpose of the Study:
- To evaluate a single metasurface with a gradient refractive index (GRIN) lens for confocal fluorescence imaging.
- To demonstrate improved image quality and simplified optical design.
- To assess the performance of a metasurface-integrated aberration-corrected lens system for compact endoscopy.
Main Methods:
- Integration of a metasurface with a GRIN lens for confocal fluorescence endoscopy.
- Design optimization where excitation and emission wavelengths focus at different planes, eliminating explicit chromatic aberration correction.
- Comparison of the hybrid meta-GRIN lens system with a system lacking a meta-element using resolution targets and biological tissue.
Main Results:
- Reflectance imaging showed a 3.5-fold contrast improvement on resolution targets.
- Fluorescence imaging of mammalian brain tissue demonstrated a 2-fold increase in contrast-to-noise ratio at intermediate to extreme fields.
- Achieved a focal spot with a 1/e^2 beamwidth of 3.1 µm (on-axis) and 3.3 µm (extreme field) over a 175 µm × 40 µm field of view.
Conclusions:
- A single metasurface combined with a GRIN lens effectively improves confocal fluorescence imaging quality in endoscopy.
- The hybrid system simplifies optical assembly and alignment compared to conventional multi-lens approaches.
- This metasurface-GRIN lens system offers a compact and portable solution for high-quality endoscopic imaging.
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