| 摘要: | 具有多光子吸收特性的材料因其在光子學及生醫光(電)子學上有許多不同應用的潛力﹐自1990年代中期以來已引起學界相當程度的注意。目前其應用方向包括﹕光學功率抑制器､頻率上轉換染料雷射､三維光記憶體材料､三維微結構製造､光動力治療法以及非破壞性生物檢測/顯相技術等。由於一般已商業化的化合物皆無較強的多光子吸收特性以敷實際應用﹐因此必須藉由分子設計並利用合成的方式來製備具有較高效能之多光子吸收度的材料以滿足各項應用與開發相關技術的需求。為有效地達成此一目的﹐在基礎研究上必須致力於有系統性地透過有機合成以微調分子的官能基及結構﹐並利用可靠的光學量測技術來探究這些分子的非線性吸收特性。基於上述考量，我們研擬了相關的研究計畫並將其分為以下三項互有關聯之研究課題： [1] 分子設計及合成具有較寬譜帶之多光子吸收特性的材料。 [2] 分子結構與其線性與非線性光學性質間關係之探討。 [3] 多光子吸收材料在光學功率抑制器及染料雷射上的應用研究。本計畫在材料的合成方面預定發展兩類不同結構的分子：第一類為「新型含雜環及不同吸光中心(absorbing centers)之共軛條狀分子」；第二類為「新型之多叉及樹枝型共軛染料分子」。將本實驗室製備出來的新型材料配合精密的光學儀器和量測技術作鑑定，由其中所得之研究結果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較深入的認識。同時，此項工作也有利於建立對材料的分子設計及應用有很大助益的分子資料庫。在這一個為期兩年的研究計畫中，我們將與本校積體光學實驗室積極地合作並期待能籌組具皮秒脈衝的光學設施以期未來能進行更深入的時域相關性的研究。另一方面，我們也將會繼續與美國紐約州立大學水牛城分校的雷射、光子學暨生物光子學中心及澳洲國立大學的雷射物理中心保持密切且互動的國際合作以便針對這些材料的非線性吸收光學性質進行多方面的探討。Broad-band multi-photon absorbing materials are of significant interest to the academic community, industry, and military for numerous applications including optical power limiting, frequency up-conversion, IR to visible optical-optical conversion, 3D data storage, photodynamic therapy and noninvasive bio-imaging. The commercialized materials are not good candidates for these applications because they possess comparatively poor nonlinear absorption properties. Therefore, for the practical purposes, it is very important to develop and explore new multi-photon absorbing materials with strong optical nonlinearity coupled with enhanced structural flexibility, ease of processing, low cost and large-scale manufacturability. In order to approach this goal, well-defined structure-property relationships must be established. This requires an investigation of large number of different structures with systematically varied molecular structural parameters by reliable characterization methods. With the aid of white-light continuum and Z-scan techniques for the degenerate nonlinear absorption spectra measurement, it is possible to investigate the dispersion of multi-photon absorbing of the studied compounds within a certain spectral range. The data obtained by these techniques provide useful information for us to study the structure-nonlinear absorption property relationships. This Proposal is composed of three correlative parts: I. Molecular Design, Synthesis and Our Goals; II. Linear and Nonlinear Optical Properties Characterization and Structure-Property Relationship Studies; III. Evaluation of the Designed Chromophores as Potential Optical Power Limiters And Laser Dyes In order to explore the structural effects on the linear/nonlinear absorption band-width, we intend to develop two classes of organic compounds for this study and for the potential applications: (i) Novel linear (quasi-1D) type chromophores with genetic scaffold of π−A−π−A−π, (ii) Novel multi-branched, star-shaped and dendritic structures based on multi-substituted olefins. For nonlinear optical properties characterization, both the methods that utilize white-light continuum beams at various time regimes to probe the spectral response of nonlinear absorption and Z-scan will be conducted. The evaluation of optical power limiting and up-converted lasing properties is planned to be carried out in nanosecond, picosecond and femtosecond regime by corresponding facilities. This two-year continuous research involves multidisciplinary efforts including materials design, chemical synthesis, optical properties characterization and testing. Before the approval of our plan to economically set-up our own optical facilities for multi-photon absorption properties studies at picosecond regime, the close interactions with our domestic and international collaborators is believed to have benefit to the progress of proposed research. The detail works involved in this Proposal and the plan of carrying out the proposed research on the yearly basis is described in detail in the end of this Proposal. 研究期間：9808 ~ 9907 |
