| 研究生: |
徐辜文正 Ku, Wen-Cheng Hsu |
|---|---|
| 論文名稱: |
磁化電漿中電磁波傳導透明現象之實驗研究 Experimental Study of Electromagnetically Induced Transparency in Magnetized Plasma |
| 指導教授: |
陳秋榮
Cheng, Chio-Zong |
| 學位類別: |
碩士 Master |
| 系所名稱: |
理學院 - 物理學系 Department of Physics |
| 論文出版年: | 2011 |
| 畢業學年度: | 99 |
| 語文別: | 英文 |
| 論文頁數: | 55 |
| 中文關鍵詞: | 磁化電漿中電磁波傳導透明現象 、磁化電漿 、電子迴旋波 |
| 外文關鍵詞: | Electromagnetically induced transparency, Magnetized plasma, Electron cyclotron wave |
| 相關次數: | 點閱:171 下載:4 |
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考慮光將會磁化電漿中電磁波傳導透明現象(EIT)已經在理論及模擬被證實過,而本篇論文研究主要是嘗試在實驗上觀察磁化電漿中的EIT 現象。磁化電漿中的 EIT 現象跟量子力學中的原子系統中的 EIT 現象是很類似的。EIT現象是利用一道高能量的電磁波(pump wave)改變物質的折射率,使得原本會被物質吸收的探測波(probe wave)可以穿透此物質。為了達到這個目的,我們發展了電磁波波包發射及偵測系統。此系統打入一波包進入磁化電漿並利用偵測系統來診測電漿的透明化現象。除了硬體系統,我們也發展了磁化電漿中電磁波追蹤的模擬程式。此程式可以在 EIT成立的條件下模擬電磁波在電漿的傳播路徑。
在波包發射系統的實驗中,在有 pump wave 的發射下,當探測波的頻率在電子迴旋頻率附近時,我們量測到反射波的振幅變小。一種可能的原因是當產生 EIT時,探測波從真空進入電漿之間的阻抗減少。
This research attempted experimental identification of the electromagnetically induced transparency (EIT) phenomena in magnetized plasma, which is predicted by theories and has been demonstrated only by numerical simulations. EIT in magnetized plasmas is a phenomenon analogous to EIT in quantum-mechanical atomic systems. Strong pump-light alters the refractive index of matter, which is originally opaque to a probe-light, so that matter becomes transparent to the probe-light. To achieve the goal, we have developed the wave packet injector system. It injects a wave packet externally into magnetized plasma and detects the transparency of the plasma by the receiver. In addition to this hardware system we have developed a numerical ray tracing code for magnetized plasmas. The code takes into account effect of the EIT, and it can simulate the wave propagation in plasmas under the EIT condition.
The packet injection experiment showed that in the presence of pump wave injection a significant reduction in the amplitude of the reflected wave packet with frequency around the electron cyclotron frequency occurred. One conceivable explanation to this result is that the impedance between the plasma and vacuum for the probe wave was reduced by creation of the EIT
wave branch in the plasma.
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