超快强激光场中纳米颗粒的电子离子发射(特邀)

Electron and Ion Emission of Nanoparticles in Ultrafast and Intense Laser Field(Invited)

在超短强激光脉冲的作用下,纳米结构表面会产生空间和时间急剧变化的局域极端近场,引发一系列动力学过程,包括表面分子及自身分子的光电子激发,电子、离子电离和碰撞等。借助先进的速度成像谱仪等装置,能够记录并解析这些过程中的光电子、离子信息。结合多种理论模型,可以深入理解纳米颗粒在强激光场下的发射动力学。这种理解不仅有助于实现纳米颗粒电离的精确调控,还为相关技术的实际应用开辟了新的可能。相关实验技术及其理论覆盖了多个学科领域,如原子、分子、凝聚态物理、化学和生物学等。综述了纳米颗粒产生、输运和诊断系统,深入分析强场-纳米颗粒体系的相关理论模型,最后总结了纳米光电子离子发射的最新研究成果,并展望未来的发展趋势。

Significance In the past thirty years,measuring laser-induced fragments generated by atoms and molecules has become a key method for exploring and understanding atomic and molecular dynamics.Nanoparticles exhibit distinct size effects and surface near-field enhancement effects compared to individual atoms,giving them unique physical and chemical properties that have created immense technological and economic value in many application fields.The exploration of interactions between femtosecond laser pulses and nanostructures has led to many breakthrough scientific technologies,significantly advancing the fields of optoelectronics,nanoelectronic devices,nanomaterial processing,photocatalysis,biotechnology,and more.Understanding the ultrafast ionization dynamics of nanostructures is crucial for comprehending the fundamental physical processes at the atomic scale when nanostructures are excited by strong laser fields.This understanding is also valuable for regulating ultrafast ionization dynamics,promoting new nanotechnologies,and developing high-performance optoelectronic materials and chips.The scientific basis for these advanced technologies and cutting-edge applications lies in understanding the microscopic physical mechanisms of interactions between laser fields and micro-nano systems.With advancements in vacuum nanobeam source technology,the interactions between laser fields and individual nanoparticles using momentum detection spectrometers can be studied.Ultrafast femtosecond lasers,with their precise control time and frequency domains,offer high peak intensities and short pulse durations.The precise control over parameters such as wavelength,polarization,pulse width,intensity,and multi-pulse delay provides unprecedented methods for accurately measuring extreme ultrafast dynamic processes in nanomaterials,exploring strong field physical effects,and developing groundbreaking disruptive technologies.Utilizing nanoparticle beam targets in velocity imaging spectrometer systems has expanded laser ionization research from atomic to larger nanoscale systems,validating numerous fundamental physical results observed in atoms and driving forward the development of practical macroscopic applications.Progress A monodisperse nano aerosol system has been proposed(Fig.5).The development of a nanoparticle aerodynamic focusing system has been reported(Fig.6).A nano velocity imaging spectrometer has been developed(Fig.7).The physical mechanism of the M3 C model has been reported(Fig.13).The analysis of electron momentum in nanostructures influenced by carrier-envelope phase has been reported(Fig.14).The femtosecond dynamics involved in the metallization of nanostructures have been explored(Fig.15).The focusing effect of electrons emitted from nanoparticles has been reported(Fig.21).Optical control of electron emission from nanostructures has been achieved(Fig.25).A strong laser-induced minimal shock wave has been reported(Fig.30).The synthesis of surface molecules on nanoparticles in a strong laser field has been reported(Fig.33).Complete optical control of laser-induced dense plasma emission has been achieved(Fig.36).Conclusions and Prospects Overall,the study of strong field ionization in nanostructures remains an emerging field,with many aspects of ultrafast electron-ion dynamics still not fully understood.Future research promises to focus on the precise control of electrons and ion emission,as well as the ultrafast measurement and manipulation of surface molecular reactions.In addition,the formation of isolated nanoscale plasmas under intense laser fields provides an excellent platform for investigating the properties of small-scale plasmas.This includes exploring complex physical processes such as the expansion of dense plasmas,identifying and measuring various ion types within plasmas,generating dense ion sources,and examining the spatiotemporal phase transitions of plasmas.