Chip-scale metalens microscope for wide-field and depth-of-field imaging

Xin Ye; Xiao Qian; Yuxin Chen; Rui Yuan; Xingjian Xiao; Chen Chen; Wei Hu; Chunyu Huang; Shining Zhu; Tao Li

doi:10.1117/1.AP.4.4.046006

Abstract

Microscopy is very important in research and industry, yet traditional optical microscopy suffers from the limited field-of-view (FOV) and depth-of-field (DOF) in high-resolution imaging. We demonstrate a simultaneous large FOV and DOF microscope imaging technology based on a chip-scale metalens device that is implemented by a SiN_x metalens array with a co- and cross-polarization multiplexed dual-phase design and dispersive spectrum zoom effect. A 4-mm × 4-mm FOV is obtained with a resolution of 1.74 μm and DOF of 200 μm within a wavelength range of 450 to 510 nm, which definitely exceeds the performance of traditional microscopes with the same resolution. Moreover, it is realized in a miniaturized compact prototype, showing an overall advantage for portable and convenient microscope technology.

Microscopes are important imaging tools that effectively expand the human eyes to the microworld for applications in scientific research, biomedical diagnosis, and industry. Besides the ultimate goal of superresolution, a new direction of this technique aims for wide field-of-view (FOV), large depth-of-field (DOF), high throughput, and compactly portable performance.1^–6 Traditional optical microscopes are established based on refractive optical elements7^,8 that are usually bulky and heavy with limitations in FOV and DOF, although they have been substantially developed. A possible solution to miniaturizing the imaging system is to use flat diffractive lenses, but the quite low efficiency and poor imaging quality prevent its imaging applications.9 Recent lensless imaging technology considerably revolutionizes the manner of imaging technology and enables the possibility of highly compact imaging devices.3^,10^–12 Nevertheless, it strongly depends on the postprocess computation that requires large resources and prior information with risk of artifacts in some cases.