A Tri-Layer Si₃N₄-on-Si Optical Phased Array With High Angular Resolution
Zhaoyang Zhang, Hui Yu, Bei Chen, Penghui Xia, Zhiyan Zhou, Qikai Huang, Tingge Dai, Yuehai Wang, Jianyi Yang
Abstract
We demonstrate a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times 256$ </tex-math></inline-formula> optical phased array based on the tri-layer Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> -on-Si platform. By optimizing the thickness and vertical position of the Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> overlay, the grating antenna exhibits a ultra-low emission rate of 13.9 dB/cm at 1550 nm and a large bandwidth of 120 nm. Based on the optimized Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> assisted grating antenna, the OPA realizes an ultra-sharp beam divergence of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.154^{\circ }\times 0.0435$ </tex-math></inline-formula> , a two-dimensional beam steering range of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$45.6^{\circ }\times 16.1$ </tex-math></inline-formula> , and a side lobe suppression ratio better than 10.8 dB.