Fernández de Cabo Raquel, González-Andrade David, Cheben Pavel, Velasco Aitor V
Instituto de Óptica Daza de Valdés, Consejo Superior de Investigaciones Científicas (CSIC), 28006 Madrid, Spain.
National Research Council Canada, Ottawa, ON K1A 0R6, Canada.
Nanomaterials (Basel). 2021 May 14;11(5):1304. doi: 10.3390/nano11051304.
Efficient power splitting is a fundamental functionality in silicon photonic integrated circuits, but state-of-the-art power-division architectures are hampered by limited operational bandwidth, high sensitivity to fabrication errors or large footprints. In particular, traditional Y-junction power splitters suffer from fundamental mode losses due to limited fabrication resolution near the junction tip. In order to circumvent this limitation, we propose a new type of high-performance Y-junction power splitter that incorporates subwavelength metamaterials. Full three-dimensional simulations show a fundamental mode excess loss below 0.1 dB in an ultra-broad bandwidth of 300 nm (1400-1700 nm) when optimized for a fabrication resolution of 50 nm, and under 0.3 dB in a 350 nm extended bandwidth (1350-1700 nm) for a 100 nm resolution. Moreover, analysis of fabrication tolerances shows robust operation for the fundamental mode to etching errors up to ±20 nm. A proof-of-concept device provides an initial validation of its operation principle, showing experimental excess losses lower than 0.2 dB in a 195 nm bandwidth for the best-case resolution scenario (i.e., 50 nm).
高效功率分配是硅光子集成电路中的一项基本功能，但目前最先进的功率分配架构受到有限的工作带宽、对制造误差的高灵敏度或大尺寸的限制。特别是，传统的Y型结功率分配器由于结尖附近制造分辨率有限而存在基模损耗。为了克服这一限制，我们提出了一种新型的高性能Y型结功率分配器，它集成了亚波长超材料。全三维模拟显示，当针对50nm的制造分辨率进行优化时，在300nm（1400 - 1700nm）的超宽带宽内，基模额外损耗低于0.1dB；对于100nm分辨率，在350nm扩展带宽（1350 - 1700nm）内低于0.3dB。此外，制造公差分析表明，对于高达±20nm的蚀刻误差，基模具有稳健的工作性能。一个概念验证器件对其工作原理进行了初步验证，在最佳分辨率情况（即50nm）下，在195nm带宽内显示出低于0.2dB的实验额外损耗。
