Ultr-intense and Ultra-fast laser-matter interaction physics

这个主要是实验性的研究项目的主要目标是在物质和飞秒脉冲的超短超强光场之间的相互作用中隐含的一套新的物理关系。 近期的主要努力将集中在两个领域：1）相当基础的等离子体物理，它产生于超高的相对相关强度（> 10^{18} W cm^{-2}）：高次谐波产生、阿秒脉冲产生、高场相互作用下德拜屏蔽的变化、激光-粒子耦合的相对论变化以及高能离子和电子的产生; 2）与玻璃和金属的超快激光材料加工有关的相当实用的光学和等离子体物理学，包括微机械加工和直接索引写入;我们也在研究与医学应用有关的生物组织的相关问题。2第一个领域可能有助于对相对论性激光-等离子体相互作用的基本理解，并可能导致与激光聚变的“快速点火器”方案相关的实际应用物理。 培训和初步实验可以在我的实验室的太瓦CPA激光器上进行，但大多数可重复的工作必须在大型国际激光系统之一上进行，例如，法国的CEA-Saclay（'Salle Chaude'）或加拿大的ALLS激光系统。第二个领域与实验有关，因为它涉及超快激光，但强度更适中。 这满足了学生在激光物质相互作用实验中的实践培训需求，并提供了一个应用和工业相关的研究组成部分，同时仍然强调科学。这项工作在我自己的实验室中使用了两个系统：一个是1 ps脉冲的133 MHz脉冲串突发激光系统，另一个是kHz和80 MHz速率的100 fs脉冲系统。该研究包括一个适度的分析和计算理论组成部分，内部和其他地方的合作，包括相对论激光等离子体相互作用的一维和二维粒子在细胞（PIC）代码模拟，以及固体的分子动力学（MD）建模。 在分析上，我们进行有效的介电模型的纳米结构材料，并在plasma.The最棘手的问题，强烈的激光等离子体相互作用物理的光束通道一直观察到新的效果，而在同一时间确定的相互作用的条件经验-一个特别困难和复杂的诊断问题，为超强激光产生的等离子体。 我的研究风格是设置干净定义/诊断的实验问题，适合与理论预测进行比较，而不是立即从现象学上追求“极端”条件。 我们在诊断和建模方面开发的专业知识非常适合像我这样规模的团队。

The main target of this mostly-experimental research program is the set of new physical relations implicit in  the interplay between matter and ultrashort ultra-intense optical fields of femtosecond pulses.  The principal near-term efforts will be concentrated in two areas:  1) fairly basic plasma physics which arises at ultra-high, relativisitically relevant intensities (> 10^{18} W  cm^{-2}):  high-harmonic generation, attosecond pulse generation, changes in Debye shielding under  high-field interactions, relativistic changes in laser-particle coupling, and generation of energetic ions and  electrons; and  2) fairly applied optical- and plasma-physics relevant to ultrafast-laser materials-processing of glasses and  metals, including micromachining and direct index-writing;  we are also studying related problems with  biotissues, relevant to medical applications.The first of these areas is likely to contribute to basic understanding of relativistic laser-plasma interactions,  and may lead to practical applied physics relevant to the 'fast ignitor' scheme of laser-fusion.  Training and  preliminary experiments can take place on the terawatt CPA laser in my laboratory, but most publishable work  must take place on one of the large international laser systems, e.g., CEA-Saclay ('Salle Chaude') in France, or  the ALLS laser system in Canada.The second area is experimentally related, in that it involves ultrafast lasers but at more moderate intensities.   This meets the needs for hands-on training of students in laser-matter interaction experiments, and provides an  applied and industrially relevant component of research while still emphasizing the science. This work uses  two systems in my own laboratories:  a 133 MHz pulsetrain burst laser system of 1 ps pulses, and a system of  100fs pulses at kHz and 80 MHz rates. The research includes a modest analytical and computational theory component, in-house and in collaboration  elsewhere, including particle-in-cell (PIC) code simulations of relativistic laser-plasma interactions in 1D and  in 2D, and also molecular dynamic (MD) modelling of solids.  Analytically, we conduct effective-dielectric  modelling of nanostructured materials, and of beam-channelling in plasmas.The thorniest problem of intense laser-plasma interaction physics has been to observe new effects while at the  same time one determines the conditions of interaction empirically -- a particularly difficult and complex  diagnostic problem for ultra-intense laser-produced plasmas.  My research style has been to set cleanly  defined/diagnosed experimental problems, suited for comparison to theoretical predictions, rather than  immediately to pursue 'extreme' conditions phenomenologically.  The expertise we have developed in  diagnostics and also in modelling are well-suited to a group the size of mine.