Yu Qianli, Guo Zhenzhao, Zhu Jiabao, Zhang Lei, Hao Peng, Xiao Jinbiao, Feng Ting, Wu Shengbao
Opt Lett. 2024 Aug 1;49(15):4326-4329. doi: 10.1364/OL.529947.
We present what we believe is the first report on a polarization-insensitive 3 × 3 silicon star-crossing utilizing a composite subwavelength metamaterial waveguide structure. Two different types of subwavelength grating metamaterials (nanohole grating and fan-shaped bent subwavelength grating) are respectively used to address diffraction issues in the crossing region and mode interference issues caused by a compact non-adiabatic design. This approach results in a device with an ultra-compact footprint of 12.68 × 10.98 µm on a standard 220 nm silicon-on-insulator (SOI) platform. Simulation results show low insertion loss (IL) values of <0.2 dB/0.3 dB and suppressed cross talk (CT) levels of <-27.2 dB/-23.6 dB for TE/TM polarizations across a wavelength range of 100 nm (1500-1600 nm). Experimental measurements of the fabricated devices confirm outstanding performance, with IL values of <0.35 dB/0.4 dB and CT levels of <-31.5 dB/-28.6 dB for TE/TM polarization in the C-band.
我们展示了我们认为的关于利用复合亚波长超材料波导结构的偏振不敏感3×3硅交叉的首份报告。分别使用两种不同类型的亚波长光栅超材料（纳米孔光栅和扇形弯曲亚波长光栅）来解决交叉区域的衍射问题以及由紧凑非绝热设计引起的模式干涉问题。这种方法在标准的220纳米绝缘体上硅（SOI）平台上得到了一个超紧凑尺寸为12.68×10.98微米的器件。模拟结果表明，在100纳米（1500 - 1600纳米）波长范围内，TE/TM偏振的插入损耗（IL）值<0.2分贝/0.3分贝，串扰（CT）水平抑制在<-27.2分贝/-23.6分贝。对制造器件的实验测量证实了其出色的性能，在C波段，TE/TM偏振的IL值<0.35分贝/0.4分贝，CT水平<-31.5分贝/-28.6分贝。
