Design of Tunable Long-period Waveguide Grating Coupler Based on LiNbO3

被引：1

作者：

Li Q.-Q. ^{[1
]}

Zhang A.-L. ^{[1
]}

Tian H.-M. ^{[1
]}

Wang Z. ^{[1
]}

机构：

[1] Communication Devices and Technology Engineering Research Center, School of Computer and Communication Engineering, Tianjin University of Technology, Tianjin

来源：

| 2017年 / Chinese Optical Society卷 / 46期

基金：

中国国家自然科学基金;

关键词：

Coupler; Electro-optic effect; Lithium niobate; Tunable; Waveguide grating;

D O I：

10.3788/gzxb20174603.0323002

中图分类号：

学科分类号：

摘要：

A tunable long-period waveguide grating coupler based on LiNbO3 was proposed. The light can be coupled effectively from the input waveguide to output waveguide through the cladding because of the long period gratings' unique feature. The effective refractive indexes of the core and cladding of the waveguide grating will change accordingly as a result of electro-optic effect when a tunable voltage is applied, making the resonance wavelength and the coupling efficiency tuned by controlling the applied tuning voltage. The effects of coupler length and the grating period on bandwidth and the coupling efficiency tuning range, and the influence of the waveguide size on the resonant wavelength tuning sensitivity were analyzed. The results show that the shorter grating period and the greater coupler length lead to the narrower bandwith and the greater coupling efficiency tuning range. In addition, the resonance wavelength tuning sensitivity decreases with the increase of waveguide width, and the influence of thickness on the resonance wavelength tuning sensitivity can be ignored. For the coupler with the grating period of 94 μm and the coupler length of 3.52 cm, the simulation results show that the resonance wavelength tuning sensitivity can reach 26.2 pm/V, and the bandwith of 3 dB as 4.5 nm, when the applied voltage varying from 0 to 200 V, the resonant wavelength change 5.24nm, and the coupling efficiency can be tuning from 1 to 0.15. © 2017, Science Press. All right reserved.

引用

共 17 条

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