Quantum-coherent molecular ensembles in plasma

该奖项将支持基于最近发现的持续工作，即空气中氧气和氮气分子中的相干旋转波包可以对高功率飞秒激光器产生令人惊讶的强大控制。波包在空气中表现为折射率小透镜，其传播为量子回波唤醒，跟随以其群速度传播的激光脉冲。根据注入延迟，注入到这些尾流中的二次脉冲可以被捕获和操纵，或者被散射出射束轴。这些结果有望允许更高的灯丝激光功率，大大延长灯丝长度，增加电子密度，增强灯丝连续性，所有这些都是飞秒灯丝应用的关键，包括太赫兹产生，远程电离，非线性光产生和大气监测，以及放电通道。拟议的实验代表了等离子体物理学的一个新方向，具有一定的学术价值：量子相干系综与等离子体的相互作用。该奖项还将支持激光-纳米粒子相互作用的另一组实验。目标是用强激光有质动力控制纳米等离子体动力学，惯性约束的高场模拟。这一高度跨学科的实验和理论工作为研究生和本科生提供了极好的培训经验。实验背后的物理思想，以及为测量极端条件下的超快过程而开发的诊断技术，对国防和工业产生了广泛的科学和技术影响。

This award will support continued work based on the recent discovery that coherent rotational wavepackets in oxygen and nitrogen molecules in air can exert surprisingly strong control over high power femtosecond laser filamentation. The wavepackets manifest themselves in air as refractive index lenslets that propagate as quantum echo wakes following the filamenting laser pulse at its group velocity. A secondary pulse injected into these wakes, depending on the injection delay, can either be trapped and steered or scattered out of the beam axis. These results promise to allow much higher filament laser power, greatly extended filament lengths, increased electron density, and enhanced filament continuity, all essential for applications of femtosecond filaments, including terahertz generation, remote ionization, nonlinear light generation and atmospheric monitoring, and channels for electrical discharges. The proposed experiments represent a novel direction in plasma physics of some intellectual merit: the interaction of quantum coherent ensembles with plasmas. The award will also support another set of experiments in laser-nanoparticle interactions. The goal is to control the nanoplasma dynamics with the strong laser ponderomotive force, the high field analogue of inertial confinement.This highly interdisciplinary experimental and theoretical work provides an excellent training experience for graduate and undergraduate students. The physical ideas underlying the experiments, and the diagnostic techniques developed to measure ultrafast processes under extreme conditions, have a broad science and technology impact, from national defense to industry.