The team led by Prof. Pei-Nan Ni at Zhengzhou University, in collaboration with the team at Beijing University of Technology, proposed a power beam splitter that integrates dielectric metasurfaces with vertical-cavity surface-emitting lasers (VCSELs). By taking advantage of the manufacturability of large-scale two-dimensional VCSEL arrays, the device realizes polarization-insensitive two-channel and multi-channel beam splitting with selectable splitting ratios, as well as polarization beam splitting with tunable splitting ratios.
To verify the effectiveness of the design, the samples were experimentally characterized. The results show that the two-channel power beam-splitter chip directs most of the emitted optical energy into two adjacent diffraction orders. The splitting ratio between the 0th and 1st orders can be tuned from 0.92 to 70, while that between the 1st and −2nd orders can be tuned from 0.01 to 80. The multi-channel power beam-splitter chip projects the beam into the ±1st orders along both the x and y axes, with a splitting ratio of 6.6:4:3:1. The polarization power splitter realizes tunable splitting ratios for left-handed circularly polarized light (LCP) and right-handed circularly polarized light (RCP), ranging from 0.06 to 1.1.
The experimental results of all designed on-chip beam splitters agree well with the simulation results, further enhancing the functional versatility of on-chip integrated metasurface-VCSELs. Compared with discrete metasurface beam splitters, the proposed devices feature a smaller footprint and higher alignment accuracy, showing promising application prospects in LiDAR, multiplexers, optical networks, and related fields.
This work, entitled “On-chip Integration of Metasurface-Based Beam Splitter with Variable Split Ratio,” was published in Laser & Photonics Reviews. Xian-Zi Pei and Lei Bao from Beijing University of Technology are the co-first authors. Prof. Yi-Yang Xie from Beijing University of Technology, Prof. Pei-Nan Ni from Zhengzhou University, Prof. Qiang Kan from the Institute of Semiconductors, Chinese Academy of Sciences, and Prof. Pei-Pei Chen from the National Center for Nanoscience and Technology are the co-corresponding authors.
