# 臺灣博碩士論文加值系統

(3.236.84.188) 您好！臺灣時間：2021/08/03 07:53

:::

### 詳目顯示

:

• 被引用:0
• 點閱:134
• 評分:
• 下載:0
• 書目收藏:0
 我們成功利用電腦產生的平面全息圖在多模波導上建立相似量子力學絕熱轉換過程的絕熱模態轉換器。這個結構有絕佳的模態轉換效率以及解決傳統模態轉換器對於決定轉換長度的困難。此外，我們對此結構進行可調波長測試，發現此裝置約有20nm的頻寬。我們利用耦合理論得到的數值解與廣角光速傳播法的結果做比較，發現兩種理論得到的結果趨勢耦合的很好。最後，我們成功利用量子力學的絕熱條件把裝置的模態轉換長度縮短至14.7mm。在此長度下，已足夠使得模態得到完美的絕熱轉換。
 We have proposed an adiabatic computer-generated planar hologram (CGPH) structure to be a mode converter. This structure has excellent mode conversion property and eases the difficulty in defining the exact conversion length. Moreover, the structure has a bandwidth of 20 nm. The results from numerical calculations based on the coupled mode theory and beam propagation simulation agree very well. We successfully reduce the length of adiabatic mode converter to 14.7mm at which the complete power transfer can be achieved.
 口試合格證明書…………………………………………………………………Ⅰ中文摘要…………………………………………………………………………ⅡAbstract……………………………………………………………………………ⅢAcknowledgements………………………………………………………………ⅣTable of contents………………………………………………………………ⅤList of figures………………………………………………………………………Ⅶ1 Introduction……………………………………………………………………11.1 Introduction………………………………………………………………11.2 Motivation…………………………………………………………………22 Theory of Multimode Waveguides……………………………………………32.1 Basic equation for electric field in optical waveguides…………………32.1.1Wave equation………………………………………………………32.1.2 Modes expression and basic formula of multimode waveguide……52.2 Effective index method……………………………………………………92.3 Finite difference wide-angle beam propagation method………………132.4 Couple mode theory……………………………………………………212.4.1 Codirectional coupling……………………………………………243 Analogy Between Waveguide Optics and Quantum Theory……………283.1 Schematic of the optical ridge waveguide used for simulation…………283.2 The adiabatic three-level system in quantum theory……………………313.3 Similarity between the waveguide optics and quantum theory…………394 Simulation Results and Discussion……………………………………………444.1 Two modes directional converter based on optical multimode waveguide………………………………………………………………444.2 Adiabatic three modes converter………………………………………484.2.1 Mode1 transfer to mode3 via an idler mode2 at the central wavelength 1.55um……………………………………………………………484.2.2 Bandwidth analysis of the Gaussian-like distribution adiabatic mode converter……………………………………………………………544.3 Shortest length for adiabatic three modes converter……………………564.3.1 Derivation of the shortest converter length……………………564.3.2 The verify of shorter convertible length……………………………585 Conclusion……………………………………………………………………62Reference…………………………………………………………………………64Appendix…………………………………………………………………………68