High Efficiency and Low Upward Reflection Silicon Nitride Grating Coupler
ZHANG Zan-yun
ZHU Hua
LI Hong-qiang
Abstract：Silicon nitride material has the advantages of low insertion loss, good thermal stability, large tolerance of fabrication and strong misalignment tolerance, and has aroused widespread concern and great interest in research.As the interface between the photonic integrated circuit and the external fiber, grating coupler has been playing an increasingly important role in many applications, because of its excellent optical coupling performance, flexible placement and easy wafer-scale test.In this paper, a perfectly vertical grating coupler based on silicon nitride material is designed using the apodized grating structure.At the wavelength of 1 550 nm, the coupling efficiency of forward transmission is 79.5％with the substrate metal mirror, and the device without metal mirror can still achieve a coupling efficiency of 57.8％.Compared with the same type of silicon grating coupler, the upward reflection loss of our device is only 0.29％, which greatly decrease the crosstalk caused by the negative second-order reflection in the optical fiber.This design provides a good reference for the actual fabrication of silicon nitride grating coupler.
Keywords：optical interconnectionphotonic integration technologygrating couplersilicon nitride
Publication Date：2018-01-01
Online Publishing Date：2026-08-28(First online date of this platform, not the publication date of the document)
Pages：6( 31-36 )