A research team from Nanjing University has developed a solution that improves metalens performance in and for microscopy applications. The researchers’ metalens-based microscope achieves both a wide field of view (FOV) and high-resolution imaging, addressing the inherent trade-off between these two critical parameters that, according to the researchers, has prevented metalenses to date from achieving performance comparable to conventional microscopes. Metalenses face significant challenges in practical microscopy applications. Off-axis aberrations, which severely restrict metalens FOV and resolution capabilities, are the primary limitations to the use of metalenses in practical microscopy. In their system architecture, the researchers used a doublet configuration of two metalenses on opposite sides of a transparent silica substrate combined with annular illumination. The two metalenses consist of silicon nitride nano-fins, crafted as high-aspect-ratio squares with precise dimensions and arranged at carefully calculated intervals. This design approach mitigates off-axis aberrations and increases resolution capabilities, thereby optimizing imaging performance. The metalens doublet configuration with annular illumination can overcome off-axis aberrations and high-resolution wide-field imaging. Courtesy of Nanjing University. “Our metalens microscope, featuring a FOV of up to 150 μm and a half-pitch-resolution of 310 nm, far exceeds the highest resolution ever reported in meta-microscopy,” said corresponding author Tao Li. The researchers’ prototype had a 1-mm FOV with a half-pitch resolution of 620 nm. Additionally, the prototype is compact, with a measurement of 4 cm × 4 cm × 5 cm. The researchers used their meta-microscope prototype to image cervical cancer cells. The system captured images of various stages of cancer development within the same FOV, revealing important cellular details such as nuclear enlargement, deformation, and division. “Our experimental results demonstrate high-quality microscopic bioimages that are comparable to those obtained from traditional microscopes within a compact prototype, highlighting its potential applications in portable and convenient settings,” said Li. According to the researchers, the technology could be used for research scenarios where traditional microscopes would be impractical. Further, it could be integrated into microelectronic devices and systems for clinical or biomedical automation. The research was published by Advanced Photonics (www.doi.org.0.1117/1.AP.7.4.046006)