1. Compact ultra-broadband light coupling on chip via nonadiabatic pumping
- Author
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Liu, Weiwei, Li, Chijun, Wang, Bing, Chai, Tianyan, Zheng, Lingzhi, Liu, Zhuoxiong, Zhang, Haoru, Ren, Shuaifei, Li, Xiaohong, Zeng, Cheng, Xia, Jinsong, and Lu, Peixiang
- Subjects
Physics - Optics - Abstract
Enlarging bandwidth capacity of the integrated photonic systems demands efficient and broadband light coupling among optical elements, which has been a vital issue in integrated photonics. Here, we have developed a compact ultra-broadband light coupling strategy based on nonadiabatic pumping in coupled optical waveguides, and experimentally demonstrated the designs in thin-film lithium niobate on insulator (LNOI) platform. We found that nonadiabatic transition would produce a decreased dispersion of the phases related to eigenstates in the waveguides. As a consequence, we realized high-efficiency directional transfer between edgestates for various wavelengths covering a 1-dB bandwidth of ~320 nm in experiment (>400 nm in simulation), with a coupling length (~50 {\mu}m) approximately 1/10 of that required in the adiabatic regime. Furthermore, we have constructed complex functional devices including beamsplitter and multiple-level cascaded networks for broadband light routing and splitting. Our work preserves significant advantages simultaneously in extending the operation bandwidth and minimizing the footprint, which demonstrates great potential for large-scale and compact photonic integration on chip.
- Published
- 2024