Infrared all-dielectric bifocal metasurface beam splitter based on the transflective structure

• Published in: Optics communications 2025-01, Vol.574, p.130808, Article 130808
• Main Authors: Ren, Yingzheng, Liang, Zhongzhu, Shi, Xiaoyan, Yang, Fuming, Zhang, Xiqing, Dai, Rui, Dong, Yongjun, Jia, Yan, Li, Sixuan, Wang, Zihan
• Format: Article
• Language: English
• ISSN: 0030-4018
• DOI: 10.1016/j.optcom.2024.130808

Based on the design concept of a transflective double-ended response structured metasurface and the Pancharatnam-Berry (PB) phase modulation mechanism, we have designed and numerically demonstrated a bifocal all-dielectric metasurface beam splitter. This device is constructed by arranging silicon nanocolumns on SiO2 substrates. The bifocal metasurface beam splitter developed in this study achieves double-ended deflected focusing beam splitting at a wavelength of 1.55 μm. The focusing efficiency at both ends exceeds 50%, the equivalent numerical aperture at both ends is greater than 0.85, and the beam splitting ratio is approximately 1.4:1. Furthermore, compared to most current single-ended response bifocal metasurfaces, the transflective bifocal metasurface beam splitter, with equal phase modulation at both ends, is anticipated to be integrated into compact optical systems that require real-time signal feedback. •The transflective bifocal metasurface beam splitter has equal phase modulation at both ends.•The transflective bifocal metasurface beam splitter can offer signal feedback.•The transflective bifocal metasurface can get different spectral ratios by designing different cell structure parameters.