Low-loss fiber grating coupler on thin film lithium niobate platform
Bin Chen,
Ziliang Ruan,
Xuancong Fan,
Zong Wang,
Jie Liu,
Chijun Li,
Kaixuan Chen,
Liu Liu
Affiliations
Bin Chen
State Key Laboratory for Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
Ziliang Ruan
State Key Laboratory for Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
Xuancong Fan
Centre for Optical and Electromagnetic Research, Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, Higher-Education Mega-Center, South China Normal University, Sci. Bldg. No. 5, Guangzhou 510006, China
Zong Wang
Centre for Optical and Electromagnetic Research, Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, Higher-Education Mega-Center, South China Normal University, Sci. Bldg. No. 5, Guangzhou 510006, China
Jie Liu
Centre for Optical and Electromagnetic Research, Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, Higher-Education Mega-Center, South China Normal University, Sci. Bldg. No. 5, Guangzhou 510006, China
Chijun Li
Centre for Optical and Electromagnetic Research, Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, Higher-Education Mega-Center, South China Normal University, Sci. Bldg. No. 5, Guangzhou 510006, China
Kaixuan Chen
Centre for Optical and Electromagnetic Research, Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, Higher-Education Mega-Center, South China Normal University, Sci. Bldg. No. 5, Guangzhou 510006, China
Liu Liu
State Key Laboratory for Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
A grating coupler with a high coupling efficiency and low back reflections is designed and demonstrated on the thin film lithium niobate platform, which facilitates an efficient interface between a lithium niobate ridge waveguide and a standard single mode fiber. The excellent performances of the present grating coupler are enabled by a cavity-assisted grating structure and a top metal mirror, even though a uniform grating is adopted as the diffractive element. Experimentally, a coupling loss of −0.89 dB at 1552 nm is demonstrated with a 1-dB bandwidth of 45 nm. Low back reflections of <−16.5 dB to the waveguide and <−13.7 dB to the fiber are also achieved from 1536 to 1579 nm.
