Non-uniform optical phased array with a large steering angle and high side mode suppression ratio
Zheng Wang, Pengfei Ma, Yi-Bo Yang, Langlin Cui, Lei Yu, Guangzhen Luo, Pengfei Wang, Jiaoqing Pan, Yanmei Su, Yejin Zhang
Abstract
An optical phased array (OPA) is one of the most promising methods of light detection and ranging. A non-uniform array with different emitter distances is a method to realize OPA steering without grating lobes or a distance between two adjacent emitters larger than <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>λ</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mo>/</mml:mo> </mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:math> . However, the side mode suppression ratio (SMSR) will decrease as OPA turns into a large angle. In this paper, 64-, 128-, and 256-channel non-uniform OPAs are optimized by non-dominated sorting genetic algorithm-II (NSGA-II), which is a multi-objective optimization algorithm. Compared with arrays optimized by a genetic algorithm, the SMSR at 80° improves by 2.18, 2.61, and 2.56 dB, respectively.