Angle-based wavefront sensing enabled by the near fields of flat optics

• Published in: Nature communications Vol. 12; no. 1; p. 6002
• Main Authors: Yi, Soongyu, Xiang, Jin, Zhou, Ming, Wu, Zhicheng, Yang, Lan, Yu, Zongfu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 14-10-2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/624/1075/1083; 639/624/1111/1116; Focal plane devices; Humanities and Social Sciences; Industrial applications; multidisciplinary; Optics; Science; Science (multidisciplinary); Sensor arrays; Sensors; Shack-Hartmann sensors; Spatial discrimination; Spatial resolution; Wave front sensors; Wave fronts
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-26169-z

There is a long history of using angle sensors to measure wavefront. The best example is the Shack-Hartmann sensor. Compared to other methods of wavefront sensing, angle-based approach is more broadly used in industrial applications and scientific research. Its wide adoption is attributed to its fully integrated setup, robustness, and fast speed. However, there is a long-standing issue in its low spatial resolution, which is limited by the size of the angle sensor. Here we report a angle-based wavefront sensor to overcome this challenge. It uses ultra-compact angle sensor built from flat optics. It is directly integrated on focal plane array. This wavefront sensor inherits all the benefits of the angle-based method. Moreover, it improves the spatial sampling density by over two orders of magnitude. The drastically improved resolution allows angle-based sensors to be used for quantitative phase imaging, enabling capabilities such as video-frame recording of high-resolution surface topography.
Generally, wavefronts are measured using angle-based sensors like the Shack-Hartmann sensor. Here, the authors present an angle-sensitive device that uses flat optics integrated on a focal plane array for compact wavefront sensing with improved resolution.