本論文主要設計與合成新型雙光子吸收材料並探討其光學性質。我們將具有良好共平面性與發光性質的indenofluorene與fluorene導入本論文中的模型分子系統，透過小心的合成與純化鑑定的過程，成功地製備出數個條型、多叉型以及樹狀型的模型分子。在線性光學性質的量測上，我們使用吸收光譜儀與螢光光譜儀來量測模型分子的最大吸收波長、最大發射波長與螢光產率。另外，我們以可調節波長的(鈦:藍寶石)飛秒雷射作為探測光源針對這些模型分子來進行其非線性光學性質的量測。由所測得的雙光子激發螢光光譜以及雙光子螢光光強與入射光強度之依賴性等實驗數據顯示這些模型分子在光譜範圍700 nm至760 nm附近有明顯的雙光子吸收行為。經系統性比較這些模型分子之雙光子激發截面，我們得到三個結果:第一，改變條型分子之共軛長度同時觀察其雙光子吸收度的變化，我們發現延伸分子的共軛長度對提升分子的雙光子吸能力有很大的幫助。第二，由分析多叉型及樹狀型的模型分子之雙光子吸收行為觀察到當π-電子非定域化的範圍隨共軛系統的往多方向延伸而擴展時，分子的雙光子吸收能力也有非常明顯的提升。第三，本論文的模型分子系統經平行比較後我們觀察到含有indenofluorene的模型分子其展現的雙光子吸收能力是優於含 fluorene的類似模型分子。 The projects involved in this thesis mainly attempted to design and synthesize some novel two-photon absorbing model compounds and investigate their optical properties. The two-photon-absorption-related properties of these model compounds were characterized by using high peak power infra-red laser pluses working in femto-second regime. By analyzing the correlation between the model compounds and the observed two-photon absorption properties, we have concluded some useful information for the molecular design: First, it is observed that the molecular two-photon absorptivity can be promoted by extending of the π-conjugation length in our compound system. Second, two-photon absorption property can be effectively enhanced if the π-delocalization domain can be properly expanded. Third, the parallel comparison of the all analogues in our model compound system indicates that indeno- fluorene is a better two-photon activity enhancer over fluorene.
