State Key Laboratory on Advanced Optical Communication Systems and Networks, Peking University, Beijing 100871, China.
Opt Lett. 2011 Jul 15;36(14):2614-7. doi: 10.1364/OL.36.002614.
A high-performance and compact fiber-to-waveguide binary blazed subwavelength grating coupler was designed based on silicon-on-insulator. By the appropriate choice of waveguide/grating parameters, including thicknesses, periods, height, and fill factor, to optimize the mode matching, a relatively high coupling efficiency was obtained for the fiber and waveguide interface. Moreover, perfectly vertical fiber coupling is achieved by using an asymmetric subgrating structure in which a period consists of two subgratings with identical etching height and different widths. Coupling efficiency as high as 69% at a wavelength of 1.52 μm and 65% at a wavelength of 1.55 μm is calculated. Simultaneously, the 1 dB wavelength bandwidth is around 80 nm. The coupling efficiency can reach up to 80% or so if Bragg reflector layers are added. Finally, the device layout is simple, feasible, one-step etched, and compatible with standard complementary metal-oxide semiconductor technology processing.
基于绝缘体上硅（SOI），设计了一种高性能、紧凑的光纤到波导二元闪耀子波长光栅耦合器。通过适当选择波导/光栅参数，包括厚度、周期、高度和填充因子，优化模式匹配，在光纤和波导界面获得了相对较高的耦合效率。此外，通过使用具有相同刻蚀高度但宽度不同的两个子光栅组成的非对称子光栅结构，可以实现完美的垂直光纤耦合。在 1.52μm 波长处计算出的耦合效率高达 69%，在 1.55μm 波长处计算出的耦合效率高达 65%。同时，1 dB 波长带宽约为 80nm。如果添加布拉格反射器层，耦合效率可高达 80%左右。最后，该器件布局简单、可行、一步刻蚀，与标准互补金属氧化物半导体（CMOS）技术处理兼容。
