Progress in microspheric lens based super-resolution microscopic imaging technology with large field of view

Optical microscope is a vital tool to explore the microscopic world for humans, which plays an important role in the fields of biology, medicine, materials science, and precision measurement. Due to the diffraction limit, developing super-resolution optical microscopy imaging technology with higher image quality and spatial resolution has become a hot research frontier. Super-resolution imaging technology based on microspheric lens has great development potential because it's obvious advantages of being easy to implement, simple operation and label-free. However, the field of view (FOV) of a single microsphere is limited, and it is difficult to locate the microspheres accurately. Improving the maneuverability of microspheres and expanding the FOV of super-resolution imaging have become the key of this technology development. Based on the principle of microsphere super-resolution imaging technology and the main factors for imaging quality, the paper focuses on the latest research progress in expanding the FOV of microspheric lens super-resolution microscopy imaging. According to the control methods of the microsphere, these progresses are summarized into four categories: Mechanically contact control, non-contact control, microsphere assembly layer, and microsphere-objective integration. The technical characteristics of these four categories are discussed, and the image processing technologies for field expansion are also analyzed, such as large FOV and image stitching. At the end, the paper points out the key problems, existing difficulties and challenges for microspheric lens super-resolution imaging technology, as well as the breakthrough for the future research work. The development direction and application future of this technology are prospected.