標題: | Z-掃描量測碲化鋅之三階非線性效應 Determination of optical nonlinearity of ZnTe by Z-scan technique |
作者: | 王蒼祺 Tsang-Chi Wang 謝文峰 Wen-Feng Hsieh 光電工程學系 |
關鍵字: | Z-掃描;碲化鋅;非線性折射係數;自旋-軌道偶合能帶;雙光子共振;z-scan;ZnTe;nonlinear refractive index;spin-orbital split band;two photon near resonant |
公開日期: | 2000 |
摘要: | 利用飛秒超短脈衝鈦藍寶石雷射(波長800nm)從事變化強度Z-掃瞄量測技術研究碲化鋅(Eg=2.26eV)。發現此樣品的非線性折射係數n2約為1.373x10-13cm2/W ,跟一般理論預測在入射光子能量是介於一半能隙和能隙之間時,n2<0,似乎不吻合。認為是自旋-軌道偶合能帶能量接近雙光子共振。非線性吸收係數的增強猜測可能是THz電磁輻射的產生導致。 By using a femtosecond Ti:sapphire laser (wavelength = 800nm) as z-scan source, we have studied intensity dependent nonlinear refractive index of the ZnTe. The positive nonlinear refractive index is observed for n2=1.373x10-13cm2/W. In regime,general theory shows that c(3)<0. The discrepancy of our result with theory is explained by two photon near-resonant to spin-orbital split band transition. Larger nonlinear absorption may be enhanced by THz generation. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#NT890614041 http://hdl.handle.net/11536/67925 |
顯示於類別: | 畢業論文 |