Guest editor: Professor Sun Shulin, Fudan University; Professor Cao Tun Dalian University of Technology; Professor Guo Yinghui, Institute of Optics and Electronics, CAS

Cover story: Feng R, Tian Y K, Liu Y L, et al. Polarization-multiplexed optical differentiation using topological metasurfaces[J]. Opto-Electron Eng, 2023, 50(9): 230172

Optical analog computing avoids the photoelectric conversion in various application scenarios by directly modulating the optical input in the spatial domain. Therefore, it has become a research focus in many applications such as image processing. In this paper, a polarization-multiplexed optical analog computing metasurface structure based on the Green's function method is designed using topologal optimization. Under different linearly polarized light incidence, this topological metasurface can independently tailor the amplitude and phase of the transmitted light field. It achieves bright-field imaging and one-dimensional second-order differentiation operations in orthogonal polarization states, as well as a polarization- controlled differentiation direction for a multiplexed differential system. These polarization-multiplexed designs can play a vital role in more optical computing application scenarios.