Opt Lett. 2019 Jan 15;44(2):211-214. doi: 10.1364/OL.44.000211.
We designed and fabricated a silica-based 16×16 cyclic arrayed waveguide grating router (AWGR) with improved channel loss uniformity using a simple mode-field converter composed of a slab coupling region and auxiliary waveguides placed at the interface between the arrayed waveguides and the output star coupler of the AWGR. The mode-field converter transforms the fundamental Gaussian-shaped mode in the arrayed waveguides to a complex mode field which produces a flat-top far field at the image plane of the output star coupler. It does not change the overall construction of the AWGR and does not increase the device size. The experimental results show that loss non-uniformity for a 16×16 AWGR with 1.6 nm wavelength channel spacing is reduced from 3 to 0.5 dB after adapting the mode-field converter, and the crosstalk is improved by about 2 dB.
我们设计并制造了一种基于二氧化硅的 16×16 环形阵列波导光栅路由器（AWGR），使用由平板耦合区和辅助波导组成的简单模式场转换器，改善了通道损耗均匀性，该转换器放置在阵列波导和 AWGR 的输出星形耦合器之间的界面上。模式场转换器将阵列波导中的基本高斯模式转换为复杂的模式场，在输出星形耦合器的像平面上产生平顶远场。它不会改变 AWGR 的整体结构，也不会增加器件尺寸。实验结果表明，在适应模式场转换器后，具有 1.6nm 波长通道间隔的 16×16 AWGR 的损耗不均匀性从 3dB 降低到 0.5dB，串扰提高了约 2dB。
