本論文的研究目的為系統性的設計並合成數個含有quinoxaline基團的模型分子，可細分為三叉型分子與條狀型分子。希望藉由改變推、拉電子基與其相對位置來促進分子內電荷轉移程度，並增加分子的π共軛長度與外圍分歧數以增加π電子非定域化之範圍以探討結構上的改變對雙光子吸收特性之影響。我們透過線性光學測量結果可得知模型分子的最大吸收波長、最大發射波長、絕對螢光量子產率以及單光子螢光生命期；透過飛秒時域雷射量測雙光子激發螢光與激發光源強度之關係證實此螢光經由雙光子吸收機制所產生、利用螢光比較法計算得到雙光子激發截面值。奈秒時域雷射則是測量模型分子在光學功率限幅行為上之表現、以及穩定脈衝雷射能量之作用。經過一系列光學量測之結果，可歸納出下列幾點：(1)改變π-電子共軛橋樑的長度可促進分子內電荷轉移程度，有助於提升雙光子激發截面；(2)若增加分子其外圍分歧數也有助於提升雙光子激發截面；(3)Quinoxaline這類官能基結構可促進內電荷轉移程度以提高雙光子激發截面並有較長的螢光生命期。The purpose of this thesis is to systematically design and synthisize a number of model molecules containing quinoxaline units. These model compounds can be catergorized into two types: symmetrically branched and unsymmetrically branched structures. We tentatively construct several model compounds with various structural parameters in order to investigate the influene that may be caused by electronic properties of the central π-bridge and the number of branches on the molecular two-photon absorptivities. After a series of linear and nonlinear optical measurements, our findings can be summarized as the following: Either the electronic nature or the length of the conjugated bridge or the number of peripheral branches in a dye molecule is closely related to the molecular two-photon absorptivities. On the other hand, it has been demonstrated that the incorperation of quinoxaline units may lead to longer excited-state lifetime, which is beneficial to the optical-control related applications.
