With the rapid development of laser technology, ultra-fast lasers have appeared in people’s sight. It has unique ultra-short pulse and ultra-strong characteristics, and can obtain extremely high peak light intensity with lower pulse energy. The emergence of ultra-short pulse chirp amplification technology has greatly improved the intensity of ultrafast green laser pointer. Unlike traditional long-pulse lasers and continuous lasers, ultra-fast lasers have ultra-short laser pulses, which makes the spectral width of laser pulses quite large.
Such a wide frequency spectrum has important applications in areas such as atomic energy level research and laser bond selection chemistry. Taking advantage of the short pulse of ultrafast laser, the pump-detection method can be used to take pictures of the interaction between the laser pulse and the substance at different times, in order to obtain the characteristics of the whole process. This method has been applied to various fields, such as in the study of atomic and molecular reaction dynamics and observation of the movement of electrons, using femtosecond laser pulses or even attosecond pulses, and observing the reaction process through the pump-probe method.
When the focused ultrafast laser has a peak power density exceeding 1012W/cm2, the electric field intensity generated is already greater than the internal electric field of the atom. It provides a very strong and extremely high electric field, which can exceed the binding force of the valence band electrons and cause great changes in the electronic system of molecules and atoms. Using this feature, one can study the peculiar phenomena generated inside atoms due to ultrafast lasers. In addition, ultrafast lasers also show other different characteristics, such as a small heat-affected area, an effect that can exceed the optical diffraction limit, and excellent spatial selection characteristics.
The interaction between ultra-fast ultra-strong laser pulses and matter is currently one of the most active research topics. It has broad application prospects in new particle accelerators, ultra-fast high-energy X-ray light sources, etc. At the same time, it contains a variety of theoretical and experimental research topics, involving many important branches of physics, such as laser physics, atomic and molecular physics, nonlinear optics, plasma physics, thermodynamics, etc. With the continuous development of ultrashort laser pulse technology.
Experiments have been able to produce high-intensity ultrashort pulses of the periodic magnitude, providing unprecedented experimental means and extreme physical conditions for the study of the interaction of light and matter, and opening up a new research field of the interaction of light and matter. The so-called extreme nonlinear optics has greatly enriched the research content of optics, and expanded the study of the interaction between laser pointer and various forms of matter such as atoms, molecules, ions, electron clusters, and plasmas to highly nonlinear and relativity The strong field range.