Development of Tunable Optical Filters for WDM Optical Communication Using High Coupling SH-Type Surface Acoustic Waves

利用高耦合SH型声表面波开发用于WDM光通信的可调谐光滤波器

• 批准号: 10555109
• 负责人: NAKAMURA Kiyoshi
• 金额: $ 7.42万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10555109/
• 关键词: SH-type surface wave; KNbOィイD23ィエD2; Tunable filter; LiNbOィイD23ィエD2; ZnO film; Optical waveguide; Acousto-optic effect; KNbO_3結晶; WDM光通信用波長可変フィルタ; Y-X LiNbO_3結晶; Ti拡散

The purpose of this research project is to develop high efficiency tunable optical filters for wavelength-division-multiplexing (WDM) optical communication by utilizing interaction between high coupling SH (shear-horizontal)-type surface acoustic waves and optical TE- and TM-mode waves. The results obtained in this project are summarized as follows : 1. It has been shown that there exists the BGS wave, which is a pure shear surface acoustic wave, on the metalized surface of Z-axis cylinder cuts of KNbOィイD23ィエD2, and the electromechanical coupling factor KィイD12ィエD1 is very high, about 53%. 2. The change of refractive index induced by the BGS wave on Z-axis cylinder cuts of KNbOィイD23ィエD2 has been analyzed and the results revealed the index change to be 18 times larger than that of the conventional Rayleigh waves. 3. By depositing a ZnO film with a low shear wave velocity on the Y-X LiNbOィイD23ィエD2 substrate the leaky SH-type surface wave is turned into a non-leaky SH-type surface wave with no propagation loss and the KィイD12ィエD1 is as high as 21.4% for the ZnO film thickness about 0.1λ. This has been experimentally proved. 4. The refractive index change induced by the SH surface wave on ZnO/Y-X LiNbOィイD23ィエD2 has been shown theoretically to be large near the substrate surface compared with those of the Rayleigh waves. The coupling length needed for 100%TE-TM mode conversion has been calculated using the coupled-mode theory to be about 1/2.5 of that of the Rayleigh wave. 5. ZnO/Y-X LiNbOィイD23ィエD2 acousto-optic tunable filters have been designed and fabricated. The experimental evaluation of TE-TM mode conversion characteristics are now under investigation.

本研究计划的目的是利用高耦合SH（剪切水平）型表面声波与光学TE和TM模波之间的相互作用，开发用于波分复用（WDM）光通信的高效可调谐光学滤波器。本项目取得的主要成果如下：1.结果表明，在KNbO_（12）D_（23）D_（12）D_（1 2.本文分析了BGS波在KNbO单晶D23单晶D2 Z轴圆柱切口上引起的折射率变化，结果表明折射率变化是常规瑞利波的18倍。3.通过在Y-X LiNbO_xD_（23）O_xD_（23）O_xD_2衬底上淀积一层低横波速度的ZnO薄膜，使漏SH型表面波转变为无传播损耗的无漏SH型表面波，当ZnO薄膜厚度为0.1λ时，K_xD_（12）O_xD_（12）O_xD_1高达21.4%。这已被实验证明。4.在ZnO/Y-X LiNbO_xD_（23）_xD_（22）上，SH表面波引起的折射率变化在靠近衬底表面处比瑞利波引起的折射率变化大。利用耦合模理论计算出100%TE-TM模转换所需的耦合长度约为瑞利波的1/2.5。5.本文设计并制作了ZnO/Y-X LiNbO双掺杂D23双掺杂D2声光可调谐滤波器。TE-TM模式转换特性的实验评估正在研究中。

项目成果

H.-B.Kang: "Growth of ZnO Thin Films on LiNbO3 Substrates by Electron Cyclotron Resonance-Assisted Molecular Beam Epitaxy"Jpn. J. Appl. Phys.. 37. 5220-5223 (1998)

H.-B.Kang：“通过电子回旋共振辅助分子束外延在 LiNbO3 基板上生长 ZnO 薄膜”Jpn。

H.-B. Kang, K. Yoshida, and K. Nakamura: "Growth of ZnO Thin Films on LiNbOィイD23ィエD2 Substrates by Electron Cyclotron Resonance-Assisted Molecular Beam Epitaxy"Jpn. J. Appl. Phys.. 37. 5220-5223 (1998)

H.-B. Kang、K. Yoshida 和 K. Nakamura：“通过电子回旋共振辅助分子束外延在 LiNbO2D23​​D2 基板上生长 ZnO 薄膜”J. Appl. 37. 5220-5223 1998）

K.Nakamura: "Sh-mode SAW and its acousto-optic interaction in KNbO_3" Proc.1998 IEEE Ultrasonics Symposium. (未発行). (1999)

K. Nakamura：“Sh 模式 SAW 及其在 KNbO_3 中的声光相互作用”Proc.1998 IEEE 超声研讨会（未出版）。

押木光博: "KNbO_3薄膜/基板構造におけるSH型弾性表面波の伝搬特性" 日本音響学会講演論文集. 957-958 (1998)

Mitsuhiro Oshiki：“KNbO_3薄膜/基底结构中SH型表面声波的传播特性”日本声学学会会议记录957-958（1998）。

押木光博: "KNbO_3結晶におけるBGS波の解析" 日本学術振興会弾性表面波素子第150委員会第56回研究会資料. 17-20 (1998)

Mitsuhiro Oshiki：“KNbO_3晶体中BGS波的分析”日本学术振兴会表面声波器件第150届委员会第56次研究会议材料17-20（1998）。