Research on Novel Short-Wavelength, Short Pulse Laser Systems

在过去的三年里，我们国家科学基金会资助的项目在短波激光光谱学、激光材料和激光等离子体相互作用领域取得了许多重要成果。我们首次利用分子的内壳光离来产生新的类准分子分子态。结果表明，激光等离子体激发技术还可用于促进新的化学反应形成分子离子。这些结果将对未来的分子短波激光方案、等离子体化学、内壳激发态分子光谱学，甚至对类星体附近致密分子云的理解产生决定性的影响。我们项目的另一个亮点是研究了激光-材料相互作用中的高强度现象，并通过直接紫外激光烧蚀生产了亚100 nm线聚合物。未来三年的计划主要集中在三个新思路上。现在进行光电离泵浦离子准分子激光器实验的时机已经成熟。在这个项目中，我们将汇集由一位研究者开创的原子短波激光的光电离泵浦的进展。第二个项目将重点研究新型紫外和甚紫外准分子（如固体激光器）的可能性。目标是将准分子的效率和可调性与固体激光器的紧凑性和相对简单性结合起来。最后，我们将探索一种新的想法，在解离分子中产生增益，我们称之为二聚体（或二聚体）激光方案。这种放大器将适用于所有解离分子状态，并且具有无与伦比的带宽，可以放大10fs范围内的脉冲。

Over the last three years, our NSF funded program let to a number of significant results in the areas of short wavelength laser spectroscopy, laser materials, and laser plasma interaction. For the first time we used inner shell photoionization of molecules to generate new, excimer like molecular states. It was demonstrated that the laser produced plasma excitation technique can also be used to promote new chemical reactions to form molecular ions. These results will have decisive impact on future schemes of molecular short wavelength lasers, plasma chemistry, the spectroscopy of inner shell excited molecules, and even the understanding of dense molecular clouds in the neighborhood of quasars. Another highlight of our program was the investigation of high intensity phenomena in laser- materials interaction and the production of sub-100 nm lines polymers by direct ultraviolet laser ablation. The proposed program for the next three years focuses on three new ideas. The time is now ripe to undertake experiments towards photoionization pumped ionic excimer lasers. In this project we will bring together the progress on photoionization pumping of atomic short wavelength lasers pioneered by one of the investigators. The second project will focus on investigating the possibility for new UV and VUV excimer like solid state lasers. The objective is to combine the efficiency and tunability if excimers with the compactness and relative simplicity of solid state lasers. Finally, we will explore a new idea to produce gain in dissociating molecules in a proposal we call the disomer (or disoplex) laser scheme. Such amplifiers would be universal for all dissociating molecular states and would have unsurpassed bandwidth for the amplification of pulses in the 10 fs range.