Geometric phase, also known as PB phase, has a profound meaning in many branches of physics, such as condensed matter physics and quantum systems, and has been extended to classical optics. Although geometric phase has a long history of research, with the development of optical research towards the sub wavelength scale, this ancient concept has been pregnant with new connotation, which brings new optical theories, micro/nano structure devices and optical applications.

In mathematics, topology is concerned with the properties of a geometric object that are preserved under continuous deformations. In physics, topology is generally manifested in the evolution of the eigenstates. With the celebrated quantum Hall effect introducing topological Chern invariants into physical systems for the first time, interesting phenomena based on topology have been vigorously developed in various fields of physics.

Information metasurfaces develop from digital coding and programmable metasurfaces, the initial idea of which is to design the metamaterials structure pattern in a digital way. Compared to previous research focusing on the material characteristics and function realization, information metasurfaces discuss from the perspective of information science and produce a totally digital pattern on metamaterial configuration by digital and discrete meta-element.

Photonics Insights will be a high-quality，peer-reviewed, Diamond Open Access journal. It will feature review articles which present the current status of a given topic, with background, research progress, conclusions, and possible future developments.