An On-Chip Calibration Method for Optical Phased Array With No Blind Spot in the Steering Range
Zhiyan Zhou, Qikai Huang, Zhaoyang Zhang, Hui Yu, Jianyi Yang, Yuehai Wang
Abstract
We demonstrate an on-chip phase calibration method in the silicon-based optical phased array (OPA) using multimode interferences (MMIs) and germanium silicon photodetectors (GeSi PDs), which are integrated at the end of the grating array. Two groups of MMIs with staggered symmetrical distribution are utilized to obtain the phase difference between adjacent gratings and linked to the PDs. With this method, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times32$ </tex-math></inline-formula> OPA with thirty-two PDs realizes a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$36.4^{\circ } \,\, \times11.5^{\circ }$ </tex-math></inline-formula> beam steering range without any blind spot, and the optimal side-lobe suppression ratio is 9.3 dB.