Experimental demonstration of a silicon nanophotonic antenna for far-field broadened optical phased arrays  

作　　者：SHAHRZAD KHAJAVI JIANHAO ZHANG PAVEL CHEBEN DANIELE MELATI JENS H.SCHMID ROSS CHERITON MARTIN VACHON SHURUI WANG AHMAD ATIEH CARLOS ALONSO RAMOS WINNIE N.YE 

机构地区：[1]Department of Electronics,Carleton University,Ottawa,Ontario K1S 5B6,Canada [2]National Research Council Canada,Ottawa,Ontario K1A 0R6,Canada [3]Centre for Nanoscience and Nanotechnologies,CNRS,UniversitéParis-Saclay,91120 Palaiseau,France [4]Optiwave Systems Inc.,Nepean,Ontario K2E 8A7,Canada

出　　处：《Photonics Research》2024年第9期1954-1961,共8页光子学研究（英文版）

基　　金：National Research Council Canada((CSTIP),(HTSN 624);Technology and Innovation Program);Natural Sciences and Engineering Research Council of Canada.

摘　　要：Optical antennas play a pivotal role in interfacing integrated photonic circuits with free-space systems.Designing antennas for optical phased arrays ideally requires achieving compact antenna apertures,wide radiation angles,and high radiation efficiency all at once,which presents a significant challenge.Here,we experimentally demonstrate a novel ultra-compact silicon grating antenna,utilizing subwavelength grating nanostructures arranged in a transversally interleaved topology to control the antenna radiation pattern.Through near-field phase engineering,we increase the antenna’s far-field beam width beyond the Fraunhofer limit for a given aperture size.The antenna incorporates a single-etch grating and a Bragg reflector implemented on a 300-nm-thick silicon-oninsulator(SOI)platform.Experimental characterizations demonstrate a beam width of 44°×52°with−3.22 dB diffraction efficiency,for an aperture size of 3.4μm×1.78μm.Furthermore,to the best of our knowledge,a novel topology of a 2D antenna array is demonstrated for the first time,leveraging evanescently coupled architecture to yield a very compact antenna array.We validated the functionality of our antenna design through its integration into this new 2D array topology.Specifically,we demonstrate a small proof-of-concept two-dimensional optical phased array with 2×4 elements and a wide beam steering range of 19.3º×39.7º.A path towards scalability and larger-scale integration is also demonstrated on the antenna array of 8×20 elements with a transverse beam steering of 31.4º.

关 键 词：ANTENNA optical ARRAYS 

分 类 号：TN820[电子电信—信息与通信工程]