以矽基板製成之新型線波導製作及非線性光學效應研究

Fabrication and Nonlinearity Study of a Novel Silicon Wire Photonics.

楊哲銘(Tse-Ming Yang)

指導教授 ： 李明昌

國立清華大學/電機資訊學院/光電工程研究所/碩士(2007年)

摘要

高效率光波導一直是發展積體光學最重要的元件，然而隨著元件積體化尺寸縮小，光波導損耗變成積體光學發展最重大的阻礙。這篇文章中我們利用簡單的蝕刻及氫鍛燒製程在SOI (Silicon-on-insulator)晶圓上製作出一種新型的矽次微米線波導，經過測量後此線波導傳播損耗及耦合損耗分別為1.26dB/cm、2.5dB/side[33]。在此實驗中我們證明矽次微米線波導在小於500mW的輸入光功率時非線性損耗並不明顯，推估其相對應的等效自由載子生命週期小於10 ns。另外我們在矽線波導中觀測到的四波混頻效應在Pump wave功率為17.8dBm時可產生約-32.84dB的轉換效率，其重要性是可在全矽晶片上製作波長轉換器並應用在分波多工系統(WDM system)上。最後我們也證實了透過施加正確的電場方向我們能控制波導內自由載子密度分布，藉由此特性我們可以進一步製作全矽晶片的光調變器。

關鍵字

矽光子學 ； 波導 ； 氫鍛燒 ； 非線性光學

並列摘要

High-performance waveguide is always the most important device in integrated silicon photonics. However, as the device size reduces, waveguide loss became significant due to surface roughness. In this paper, we demonstrated a novel silicon wire waveguide on SOI wafers by a simple etching and hydrogen annealing process. According to the measurement, the propagation loss and coupler loss of silicon wire waveguide are 1.26dB/cm and 2.5dB/side[33], respectively we also demonstrated that the nonlinear loss in this silicon wire waveguide was not obvious when the input power was lower than 500mW. We calculated the effective free carrier lifetime shorter than 10ns. Additionally, we observed the four-wave mixing in the silicon wire waveguide, and the maximum conversion efficiency was -32.84dB when the pump power was as high as 17.8dBm. The importance of four-wave mixing could be used for wavelength conversion in DWDM system. Finally, we demonstrated that we could control the free carrier density distribution in the si-wire waveguide by applying electric field at the two sides. Via this mechanism, we can implement a silicon-based optical modulator.

並列關鍵字

Silicon photonics ； Waveguide ； Hydrogen annealing ； Nonlinear optics

參考文獻

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[4] Lee, K. K., D. R. Lim, et al. (2001). "Fabrication of ultralow-loss Si/SiO2 waveguides by roughness reduction." Optics Letters 26(23): 1888-1890.

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