Ultracompact multimode meta-microscope

Microscopic imaging technology is an indispensable foundation in the biomedical field, which enables powerful capability in bio-investigations. Aiming for more convenience and adaptability, a multifunctional microscope with a miniaturized scheme is a new requirement, but remains a challenge. Here, we propose an ultracompact microscope based on both spatial and guided-wave illumination that can work in bright-field, dark-field, and fluorescence imaging modes separately and simultaneously by conveniently switching the light source. The proposed guided-wave illumination not only provides a noise-free imaging mode, but also further reduces the system size. Moreover, a metalens array is specifically designed by a hexagonal arrangement to enable multi-field imaging and enlarge the field of view. The experiment results demonstrate that the half-pitch resolution is about 714 nm with an imaging magnification of 3.5×, with a field of view of 0.543 mm 2 and a space-bandwidth product of 4.26 megapixels. As examples, the multimode microscope is applied to image different cells and flowing microspheres in microtubules, showing comparable image quality with the images taken through the traditional microscope under guided-wave illumination. This demonstrates the possibility of the meta-microscope to be combined with microfluidic technology and further realize miniaturized microfluidic imaging systems. Our ultracompact multimode microscope has shown powerful capabilities for a new scheme of bio-observation and investigations.