Optical sectioning fluorescence microscopy using variable metalens

• Main Authors: Chu, Cheng Hung, Vyas, Sunil, Kuo, Hsin Yu, Chia, Yu Hsin, Chen, Mu Ku, Huang, Yi-You, Tsai, Din Ping, Luo, Yuan
• Format: Conference Proceeding
• Language: English
• Published: SPIE 20.09.2023
• ISBN: 9781510663435; 1510663436
• ISSN: 0277-786X
• DOI: 10.1117/12.3007925

Fluorescence microscopy is a common method to observe the structural features of biological samples. Conventional tunable lenses are usually used to axially scan the volumetric samples for obtaining fluorescence optical sectioning images. However, they suffer from spherical aberration and distortions. In this work, we propose a compact imaging system with optical sectioning capability based on Moiré metalens which consists of two complementary phase metasurfaces to perform fluorescence bio-imaging applications in visible regions. The focal length of system can be tuned from 10 mm to 125 mm at the wavelength of 532 nm by changing mutual angles between two metasurfaces. In addition, the speckle illumination HiLo microscope is used to reduce the effect of out-of-focus light scattering. To demonstrate the optical sectioning capability of our system, the labeled beads as well as ex vivo mice intestine tissue samples are imaged. The presented design of varifocal metalens is anticipated to realize important applications in fluorescence microscopy and endoscopy.