本計畫為期兩年，我們預定開發數個具高效能之三與四光子吸收特性的分子系統並研究其非線性光物理及光功率限幅性質。本計畫的任務主要含以下兩部分:[1] 開發新穎結構單元並用以合成具高效能之三/四光子吸收特性的多分歧型分子；[2] 探索模型分子結構與其光物理性質間的關聯性並鑑定其光功率限幅性質。在此計畫中的材料合成方面，我們擬開發具有雜環稠合的核心結構單元並利用這些核心衍生出數個具多叉構形的模型分子系統。在光學性質鑑定方面，我們將利用可調整波長(700-2000 nm)的奈秒雷射與飛秒雷射作為探測光源來量測不同時域下的多光子吸收光譜與多光子誘發之螢光光譜。同時，對於具有寬譜帶多光子吸收的模型分子，我們也將進一步研究其在不同時域與不同激發波長下的光功率限幅性質。這些數據將有助於我們對材料的分子結構與其非線性吸收行為間之關聯性有更深入的認識。 ;In this two-year proposed research project, we aim to explore the molecular design strategies toward three- and four-photon absorbing (3PA/4PA) chromophores. Two correlative missions are involved in the proposed research: [1] Molecular design and synthesis of highly active 3PA/4PA dendritic structures; [2] Structure-nonlinear property relationship studies and optical power-limiting property characterizations.In order to explore the structural effects on the molecular nonlinear absorption behaviors, we intend to develop new pi-centers containing various fused heterocycles and utilize these coplanar cores to develop novel multi-branched frameworks that exhibit strong three- and four-photon properties.For the optical properties characterization, both wavelength-tunable nanosecond and femtosecond lasers will be invoked to probe multi-photon absorption and fluorescence properties within the spectral range of 700-2000 nm. The study of optical power limiting properties of the proposed materials is planned to be carried out for the model compounds with superior 3PA and 4PA. The results obtained from the proposed research are beneficial for understanding the relationship between molecular structure and 3PA/4PA properties. The detail works involved in this Proposal and the time-table to carry out the proposed research is described in detail in the text body of this Proposal.
