質子交換與退火式質子交換鈮酸鋰藍光波導元件之研製

Fabrication of Proton Exchange and Annealed Proton Exchange Blue-Laser Waveguides on Lithium Niobate

吳正一(Jheng-Yi Wu)

指導教授 ： 王維新

國立臺灣大學/電機資訊學院/光電工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.02273

摘要

本論文探討在Z切鈮酸鋰基板上，利用質子交換以及退火式質子交換製程所設計製作的光波導及方向耦合器，並使其操作在波長為0.473um的藍光波段下導通單模態。文中主要討論製程特性、波導輸出光場、方向耦合器的耦合長度以及藍光波段下的光折效應。
　　在光場模態輸出模擬的部分，採用光束傳播法，配合質子交換波導與退火式質子交換波導的折射率模型，模擬不同的波導條件。在實際製作上，本研究成功製作在藍光波段下導通單模態的退火式質子交換波導，而實驗中所得到條件與模擬的結果有相當程度的吻合。本研究並利用藍光波段下導通單模態的製程條件成功製作藍光方向耦合器，並對其輸出光場及耦合長度進行測量，結果顯示在波導寬度為2.8um，波導間距為3.5um的條件下，耦合長度為0.441mm。在光折效應的量測部分，則針對了直波導以及方向耦合器進行測量，和文獻上的結果進行比較後，實驗結果顯示質子交換波導和傳統鈦擴散式波導相較之下，光折效應的影響較小。而退火式質子交換方向耦合器在作用長度為1600um的條件下，耦合分量受到光折效應的影響由0.152上升至0.175。

關鍵字

藍光 ； 鈮酸鋰 ； 質子交換 ； 熱退火 ； 方向耦合器 ； 光折效應

並列摘要

In this thesis, optical waveguides and directional couplers are made by proton exchange and annealed proton exchange process on Z-cut lithium niobate(LiNbO3), and are operated at blue-laser wavelength with single mode. In particular, process characteristics, output field countours, coupling length of directional coupler, and photorefractive effect caused by blue laser are discussed.
Optical mode simulation is based on the beam propagation method with refractive index models of proton exchange and annealed proton exchange waveguides, and waveguides with different conditions are discussed. In experiment, annealed proton exchanged waveguides supporting single mode at blue-laser wavelength are fabricated. The experimental results of waveguide width agree quite well with that obtained by simulation. Moreover, directional coupler is fabricated and measured under the single-mode process condition, Experimental data show the coupling length is 0.441mm when the waveguide width is 2.8um and the gap is 3.5um. Photorefractive effect is also measured for straight waveguides and directional couplers. Experimental results reveal that photorefractive effect of proton exchanged waveguides are less significant in comparison with that of Ti-diffused waveguides. The coupling ratio of directional coupler with a coupling length of 1600um is varied from 0.152 to 0.175 due to photorefractive effect.

並列關鍵字

blue laser ； lithium niobate ； proton exchange ； anneal ； directional coupler ； photorefractive effect

參考文獻

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