- 學位論文
鈦擴散鈮酸鋰多模干涉光功率分離器改良設計與研製
Improved Design and Fabrication of Titanium Diffused Lithium Niobate Multimode Interference Power Splitters
摘要
本論文之目的在探討改良式1×4鈦擴散鈮酸鋰多模干涉分光器。改良方式有採用二階式干涉區與外加電極於干涉區等兩種。 第一種多模干涉分光器係將傳統式多模干涉區適當裁剪而成。為評估元件改良效果，本文提出一改良參數作為評估標準。經適當設計二階式干涉區後，傳輸率可提升至80.5%，耦合長度可縮短至2250μm，改良參數可提高16%。 第二種多模干涉器係利用電光調變性質將干涉區前1/3段外加電壓0至60V，發現在耦合長度2250μm時，可提升傳輸率5.4%，同時內側與外側輸出波導功率比值可調變幅度為0.74至1.58，可作為可調式分光器之用。
並列摘要
Two types of improved 1×4 titanium diffused lithium niobate multimode interference (MMI) power splitters are proposed. The first MMI has an interference region of two stages adjusted to enhance an improvement factor. The second one has an interference region with deposited electrodes. The first type MMI power splitter is obtained by an appropriate cutting of the interference region. For performance evaluation of proposed device, an improvement factor is proposed. The two-stage MMI power splitter has a higher transmission of 80.5% and a shorter coupling length of 2250μm. The improvement factor is increased by 16%. For the second type of MMI power splitter, a voltage varying from 0 to 60V is applied on the first one-third of the interference region for electro-optic modulation. The results show when the coupling length is 2250μm, transmission can be increased by 5.4%, and the power ratio of inner output waveguide and outer output waveguide is varying from 0.74 to 1.58, which can be used as tunable power splitter for practical application.