Multi photon ionization (MPI) in plasma is examined in terms of optical metric, and the quantum Volkov state in curved space time is derived. The cross section of MPI is derived by virtue of the corrected Volkov sta...Multi photon ionization (MPI) in plasma is examined in terms of optical metric, and the quantum Volkov state in curved space time is derived. The cross section of MPI is derived by virtue of the corrected Volkov state within the framework of quantum electrodynamics (QED) formal scattering theory. It shows that the plasma medium acts as a suppression on MPI.展开更多
When laser intensity varies, the ionization induced by optical field can be described by multiphoton ionization （MPI） in low regime and tunneling ionization （TI） in high regime. An empirical formula was used to fi...When laser intensity varies, the ionization induced by optical field can be described by multiphoton ionization （MPI） in low regime and tunneling ionization （TI） in high regime. An empirical formula was used to fit the ionization happened between these two limitation ionization processes. Based on this, ionization rate and photocurrent induced by two-color femtosecond laser pulses interaction with air-plasma were investigated numerically. It was found that they have different relations with the laser intensity.展开更多
The controllable periodic M-shape gratings are fabricated on the surface of silica glass by three coplanar interfering beams from a single femtosecond pulse. The configuration of the M-shape periodic structure is char...The controllable periodic M-shape gratings are fabricated on the surface of silica glass by three coplanar interfering beams from a single femtosecond pulse. The configuration of the M-shape periodic structure is characterized by optical microscopy and atomic force microscopy. The experimental results and the theoretical simulation show that the period and the modulation depth ratio between the neighboring grooves of the fabricated gratings can be controlled by adjusting the collision angles and pulse energy of the three beams, respectively.展开更多
利用脉冲激光束与分子的相互作用 ,对 L i I进行了光离解。同时 ,用另一束可调谐激光对 L i I离解后产生的中性 L i进行共振激发 ,然后把处在激发态的 L i进行光电离。对 L i的飞行时间质谱 (TOFMS)进行了研究 ,并对光离解及光电离过程...利用脉冲激光束与分子的相互作用 ,对 L i I进行了光离解。同时 ,用另一束可调谐激光对 L i I离解后产生的中性 L i进行共振激发 ,然后把处在激发态的 L i进行光电离。对 L i的飞行时间质谱 (TOFMS)进行了研究 ,并对光离解及光电离过程中可能存在的多光子电离 (MPI)展开更多
The time-resolved photoelectron spectrum (TRPES) of RbI molecule is simulated using the time-dependent wave-packet method. Both the normal three-photon ionization process and auto-ionization process are involved in th...The time-resolved photoelectron spectrum (TRPES) of RbI molecule is simulated using the time-dependent wave-packet method. Both the normal three-photon ionization process and auto-ionization process are involved in the simulation. The calculated results show that the change of delay time will influence the shape of the photoelectron spectrum (PES), and the influence is sub- stantially due to the existence of the crossing between excited states and the strong laser field which will change the position of relevant curves.展开更多
文摘Multi photon ionization (MPI) in plasma is examined in terms of optical metric, and the quantum Volkov state in curved space time is derived. The cross section of MPI is derived by virtue of the corrected Volkov state within the framework of quantum electrodynamics (QED) formal scattering theory. It shows that the plasma medium acts as a suppression on MPI.
文摘When laser intensity varies, the ionization induced by optical field can be described by multiphoton ionization （MPI） in low regime and tunneling ionization （TI） in high regime. An empirical formula was used to fit the ionization happened between these two limitation ionization processes. Based on this, ionization rate and photocurrent induced by two-color femtosecond laser pulses interaction with air-plasma were investigated numerically. It was found that they have different relations with the laser intensity.
基金Project supported by the Science and Technology Key Program of Shandong Province,China (Grant No 2008GG10004020)the Program of Excellent Team in the Harbin Institute of Technology,China
文摘The controllable periodic M-shape gratings are fabricated on the surface of silica glass by three coplanar interfering beams from a single femtosecond pulse. The configuration of the M-shape periodic structure is characterized by optical microscopy and atomic force microscopy. The experimental results and the theoretical simulation show that the period and the modulation depth ratio between the neighboring grooves of the fabricated gratings can be controlled by adjusting the collision angles and pulse energy of the three beams, respectively.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos.10474060 and 10574083) the Natural Science Foundation of Shandong Province of China (Grant No. Y2003A02).
文摘The time-resolved photoelectron spectrum (TRPES) of RbI molecule is simulated using the time-dependent wave-packet method. Both the normal three-photon ionization process and auto-ionization process are involved in the simulation. The calculated results show that the change of delay time will influence the shape of the photoelectron spectrum (PES), and the influence is sub- stantially due to the existence of the crossing between excited states and the strong laser field which will change the position of relevant curves.
