Short-wavelength photon and electron emission in free and deposited nanoparticles by controlled ultrafast laserinduced nanolocalized fields

通过受控超快激光诱导纳米局域场在自由和沉积纳米粒子中发射短波长光子和电子

• 批准号: 138341798
• 负责人: Professor Dr. Thomas Fennel
• 金额: --
• 依托单位: National Accelerator Laboratory SLAC
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/138341798?language=en
• 关键词: Short; wavelength; photon; electron; emission

The emission of short-wavelength photons and electrons from nanoscopic matter of well-defined size and structure in controlled ultrafast nanolocalized laser fields is investigated. This requires the close collaboration of three research teams from physical chemistry, experimental physics, and theoretical physics. Femtosecond and few-cycle laser pulses are employed to excite isolated nanoparticles as well as arrays of ordered nanoparticles. This allows us to determine the intrinsic properties of nanoparticles, with respect to short wavelength photon emission and electron emission in intense laser and ultrashort laser fields, where the internal composition, size, and shape of the particles are systematically varied. Specifically, we expect focusing effects, if the particle size becomes similar to the wavelength of the exciting photons. Intense fewcycle laser pulses have the specific advantage that metallization of dielectric nanoparticles, nonlinear emission processes, and the emission of short-wavelength photons can be studied, where the interplay between electron emission and formation of short-wavelength radiation is of specific interest. We will also distinguish the coherent and incoherent fractions of the emitted radiation, so that the formation of highharmonics is characterized. Further, control mechanisms of electron and short-wavelength photon emission by using the carrier envelope phase as well as the superposition of the fundamental and the second harmonic of a femtosecond laser pulse are investigated. Theoretical model simulations are of primary importance for assigning the experimental signatures to corresponding microscopic mechanisms and for guiding the experiments by identifying relevant parameter regimes. Based on previous work, a Mie-Monte- Carlo model will be developed in order to study propagation effects in large nanoparticles close to the ionization threshold. Specifically, nanofocusing, evanescent near fields, and local trapping induced by ionization are explored for nanoscopic systems. Furthermore, a novel particle in cell technique will be applied and developed further in order to model the metallization of dielectric nanomaterials, plasma waves, and nonlinearities of dielectric response.

研究了在受控超快纳米局域激光场中，具有明确尺寸和结构的纳米级物质的短波长光子和电子的发射。这需要物理化学、实验物理和理论物理三个研究团队的密切合作。飞秒和几个周期的激光脉冲被用来激发孤立的纳米粒子以及有序的纳米粒子阵列。这使我们能够确定纳米颗粒的固有特性，相对于短波长光子发射和电子发射在强激光和超短激光场，其中颗粒的内部组成，尺寸和形状是系统地变化的。具体地说，如果粒子大小变得与激发光子的波长相似，我们预计会产生聚焦效应。强烈的fewcycle激光脉冲具有特定的优点，即可以研究电介质纳米颗粒的金属化、非线性发射过程和短波长光子的发射，其中电子发射和短波长辐射的形成之间的相互作用是特别感兴趣的。我们还将区分相干和非相干部分的发射辐射，使形成的高次谐波的特点。进一步研究了利用飞秒激光脉冲的载波包络相位以及基波和二次谐波的叠加来控制电子和短波长光子发射的机制。理论模型模拟对于将实验特征分配给相应的微观机制以及通过识别相关参数机制来指导实验是至关重要的。基于以前的工作，一个米氏蒙特卡罗模型将被开发，以研究在大纳米粒子的电离阈值附近的传播效应。具体而言，纳米聚焦，倏逝近场，和局部捕获电离诱导的纳米系统进行了探索。此外，一种新的粒子在细胞技术将被应用和进一步发展，以模拟介电纳米材料的金属化，等离子体波，和介电响应的非线性。