Extreme nonlinear optics in atomic multi-level systems

激光源的单周期脉冲为飞秒和阿秒时间尺度上的电子量子动力学开辟了一个独特的视角。主要的脉冲参数是载波包络偏移相位（CEO-phase，CEP），描述了光载波和脉冲包络之间的相对相位。本项目的主题是单周期脉冲照明的简单多能级束缚量子系统中粒子数的CEO依赖性。当不同相位的非线性量子路径在激发态中干涉时，预期对CEP的依赖性。这意味着当可以提供超过一个倍频程带宽的光谱时，可能的量子路径干涉实验的数量强烈增加。预期多周期脉冲不会产生CEP效应。虽然这种情况的理论模型是建立良好的，我们在这里提出的实验研究的约束电子的动力学的影响下的单周期激光脉冲的第一次。脉冲的产生基于双色泵浦参量放大器系统，产生具有高重复率的可靠的单周期脉冲。光谱跨越一个半倍频程，并将受到基于LCD的脉冲整形器的相位操纵。自适应方案允许脉冲表征，脉冲压缩，并最终用于详细的相位操纵，以在简单的量子系统（例如原子射流）中执行相干控制的多光子激发。在实验之前和平行于实验，量子系统是通过在单周期脉冲的影响下求解半经典光学布洛赫方程的理论研究的主题。直接访问基础理论允许立即分析测量数据，并深入了解原子或固态量子系统在以前从未实验研究过的参数范围内的丰富线性和非线性物理。

Single-cycle pulses from laser sources open up a unique viewpoint onto the electronic quantum dynamics on femto- and attosecond time scales. Major pulse parameter is the carrier envelope offset phase (CEO-phase, CEP), describing the relative phase between the optical carrier and the pulse envelope. Subject of this project is the CEO dependence of the population in simple multi-level bound quantum systems illumi-nated by single-cycle pulses. Dependence to the CEP is expected in the case when nonlinear quantum paths of different phase interfere in the exited state. This means that the number of possible quantum path interference experiments increases strongly when spectra beyond one octave of bandwidth can be provided. No CEP effect is expected with multi-cycle pulses. While the theoretical modeling of this situation is well established, we here propose the experimental investigation of the dynamics of bound electrons under the influence of single-cycle laser pulses for the first time. The generation of the pulses is based on a two-color pumped parametric amplifier system, generating reliably single-cycle pulses with high repetition rate. The spectra are spanning one and a half octaves and will be subject of phase manipulation by a LCD based pulse shaper. The adaptive scheme allows for pulse characterization, pulse compression, and finally for detailed phase manipulation to perform coherently controlled multi-photon excitations in simple quantum systems (e.g. atomic jets). Before and in parallel to the experiments the quantum system is subject of theoretical investigation by solving the semi-classical optical Bloch equations under the influence of the single-cycle pulses. The direct access to the underlying theory allows for immediate analysis of the measured data and for deep insight into the rich linear and nonlinear physics of atomic or solid-state quantum systems in a parameter range never investigated experimentally before.