Shape Change Caused By Interaction Between Fundamental-mode Gaussian Laser And High-energy Electron

As an extremely important tool for studying the interaction between high field and matter,ultra-intense and ultra-short pulse laser is basically generated by the principle — the low-energy pulse laser is broadened by a stretcher,and compressed back to its original width through a compressor after the enlargement.In that ultra-short pulse laser can be mathematically described as superposition of corresponding laser beams,the study of interaction between ultra-intense and ultra-short pulse and matter can be theoretically attributed to research on the interaction between laser beam and matter.From the previous experimental and theoretical studies,single-shot laser electron acceleration fails to enable electrons to gain high energy,and results in fairly little energy consumption of laser compared with the energy of laser itself.If the same laser beam can accelerate electrons many times,it will have very important application value.In the processof multiple acceleration,the wave packet change brought about by laser electron acceleration is an important issue.In the paper,the wave packet changes caused by interaction between Gaussian laser and electron are calculated.To begin with,Fourier Transform of fundamental-mode Gaussian laser is calculated.Moreover,the quantum electrodynamics method is adopted to calculate the interaction between electron and photon.Besides,the probability and mean value of outgoing photons in the electronic static coordinate system are calculated.Ultimately,the wave packet change of fundamental-mode Gaussian laser beam is obtained based on the Steepest Descent Method.