新型中空光波導研製與應用

Fabrication and application of novel hollow optical waveguide

羅仕守(Shih-Shou Lo)

指導教授 ： 陳啟昌

國立中央大學/理學院/光電科學研究所/博士(2005年)

摘要

在這個研究中，我們使用晶片鍵合的方法去製作一個以二氧化矽(SiO2)與矽(Si)薄膜組成的全方向反射鏡，利用這個全方位反射鏡在半導體基材中製作出中空型光波導，我們簡稱SHOW-ODR。相關薄膜參數為矽折射率(3.48)與二氧化矽折射率(1.48)，結構中二氧化矽薄膜與矽薄膜的厚度分別為0.258微米與0.111微米. SHOW-ODR的形成是透過稀釋的氫氧化鉀(KOH)溶液，藉由非晶系矽晶片鍵合的動作，把兩片在矽晶片上製作出相同的全方向反射鏡鍵合在一起。從穿透光譜量測值中顯示SHOW-ODR結構對於橫向電波(TE)模態與橫向磁波IS模態的傳輸損耗分別為1.0±0.3(dB/cm)與1.0±0.4(dB/cm)，結構上具有低傳輸損耗與低偏振相關的特性。
此外， 利用SHOW-ODR結構，展示分光比一比一的中空型多模干涉(MMI)分光器，在這中空MMI分光器結構前端，我們設計一個橫向的漏斗(Taper)，做為改善SHOW-ODR與單模光纖(SMF)的耦合效率。最後結果顯示中空MMI具有弱偏振相關性，同時由於核心(core)折射率較低，也使元件的長度比傳統介電值波導所製作的MMI元件還要短。因此我們相信SHOW-ODR的應用很快就會到來。

關鍵字

光子晶體 ； 波導 ； 晶片鍵合 ； 輻射模態 ； 多層膜 ； 薄膜 ； 耦合元件 ； 多膜干涉

並列摘要

In this study, a wafer-bonding approach was used to fabricate a semiconductor hollow optical waveguide formed from an omni-directional reflector (SHOW-ODR). The thin-film parameters are n1(Is) =3.48 and n2(SiO2)=1.48. The thickness of the Is and SiO2 layers was one quarter of the wavelength of 1.55?m in the materials 0.111?m and 0.258?m, respectively. The SHOW-ODR is formed by amorphous-Is wafer bonding through dilute KOH solvent. The measured transmission spectra indicate propagation losses of around 1.0±0.3 and 1.0±0.4dB/cm in TE and TM modes, respectively. The propagation loss was low and the dependence on polarization was weak.
Additionally, SHOW-ODR is used to demonstrate an MMI power splitter with a power-splitting ratio of 1:1. A lateral taper structure was introduced between the SHOW-ODR and the single-mode fiber (SMF) to increase the coupling efficiency and the tolerance of misalignment. The hollow MMI coupler exhibits a weak dependence on polarization in TE and TM modes. Moreover, the coupler is shorter than the conventional dielectric MMI because the core index is lower. We assert that the age of the applications of SHOW-ODR in OIC will come soon.

並列關鍵字

waveguides ； photonic crystals ； wafer bonding ； radiation mode ； multilayer ； thin-film ； coupler ； multimode interference

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