Quantum-coherent molecular ensembles in plasma

该奖项将支持基于最近发现的持续工作，即空气中氧和氮分子中的相干旋转波包可以对高功率飞秒激光灯丝施加惊人的强大控制。波包在空气中表现为折射率透镜，以量子回波尾迹的形式跟随长丝激光脉冲以群速度传播。注入这些尾迹的二次脉冲，取决于注入的延迟，要么被困住，要么被引导，要么被散射出光束轴。这些结果有望实现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，这些都是飞秒灯丝应用的必要条件，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。提出的实验代表了等离子体物理学的一个新方向，具有一定的智力价值：量子相干系综与等离子体的相互作用。该奖项还将支持另一组关于激光-纳米粒子相互作用的实验。目的是利用强激光质动势，即惯性约束的高场模拟来控制纳米等离子体动力学。这项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训练经验。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，从国防到工业，都具有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.