皮秒時間解析紫外光激發真空紫外光探測雷射系統之發展建制

Abstract

許多研究分子動態的實驗，都需要將樣品在儀器內游離(ionization)後才可進行分析。而相較於使用長波長雷射在強聚焦下多光子游離樣品，使用短波長的真空紫外光進行單光子游離為較軟性的游離方式，造成的碎片較少，在分析上較為便利，但是根據真空紫外光的光子能量高低，對於造成的碎片數量也會有影響，因此最好能根據欲研究的樣品選擇游離的真空紫外光波長。 本論文的主題即為探討如何在實驗室現有的條件下分別嘗試使用三倍頻、共振加強四波混成以及高階諧波生等非線性光學的方式產生不同波長的真空紫外光並投入皮秒時間解析的紫外光激發真空紫外光探測實驗中使用。

Numerous molecular dynamic researches need to ionize the sample in the instrument to analysis. Compare to multiphoton ionization (ionize the sample with longer wavelength laser under the tight focusing geometry), single photon ionization with vacuum ultraviolet laser is a relatively soft ionization source which causes less fragments and make it easier to analysis. But the amount of the fragments are also depend on the vacuum ultraviolet laser wavelength we used. So it would be better if we can adjust the vacuum ultraviolet laser wavelength depend on which sample we chose. The main topics of this thesis is to generate vacuum ultraviolet laser based on the instruments now available in the lab through nonlinear optics like frequency tripling, high order harmonic generation and resonance enhanced four wave mixing. And introduce them into the picosecond time-resolved UV-VUV pump-probe laser system.