Investigation of microsphere-assisted super-resolution imaging

The microscopy assisted by dielectric microspheres has emerged as an effective way to improve the imaging resolution of conventional optical microscope. The photonic nanojet(PNJ) is simulated by software, and super-resolution imaging experiments are carried out successfully. The results show that the silica(SiO2) microsphere with low refractive index can visualize a grating containing 139-nm-width lines with an interspacing of 139 nm under visible light illumination when it is partially immersed in alcohol. However, the barium titanate glass(BTG) microspheres with high refractive index can achieve super-resolution imaging only fully immersed in alcohol.