High-efficiency chirped grating couplers on lithium niobate on insulator
Shuting Kang, Ru Zhang, Zhenzhong Hao, Di Jia, Feng Gao, Bo Fang, Guoquan Zhang, Jingjun Xu
Abstract
High-efficiency chirped grating couplers (GCs) with coupling efficiencies (CE) approaching 90%/coupler were designed by using a particle swarm optimization algorithm. These GCs were fabricated on $z$-cut lithium niobate on insulator (LNOI) with an Au layer on the lithium niobate substrate. The maximum CEs for transverse electric and transverse magnetic polarization input were measured up to ${\sim}{72.0}\%$/coupler and ${\sim}{61.6}\%$/coupler, respectively, which are the state-of-the-art values for LNOI GCs as far as we know. These GCs contribute to the realization of high-efficiency LNOI on-chip integrated optics.
Topics & Concepts
Lithium niobateMaterials scienceOpticsGratingInsulator (electricity)Silicon on insulatorOptoelectronicsPolarization (electrochemistry)Diffraction efficiencySiliconPhysicsChemistryPhysical chemistryPhotonic and Optical DevicesPhotorefractive and Nonlinear OpticsAdvanced Fiber Laser Technologies