The Field Of Optical Thin Film Damage Under High-power Laser Research

Inertial Confinement Fusion (ICF) is an important approach to solve the human energy problem, but it has been difficult to make the interaction laser power reach the critical power. The development trend of ICF technology is to make the irradiation laser pulse more shorter and the power more higher in the world. Optical film which is one of the important components in solid laser instrument is apt to damage, so it limits the output of the laser power. As the laser pulse become shorter, the field damage form is from thermal into field, so the study of field damage mechanism for the optical film is necessary for the ICF.In the paper, theory and numerical methods are used to study the micro damage mechanism of the field, and then the problem of laser standing wave are also discussed.In chapter one, the status and tendency for the study of film are introduced at home and abroad.In chapter two, we mainly describe the fundamental theory of the optical film damage. The definition of film laser damage, some damage theory models and the methods to improve the damage threshold value of the optical film are introduced in this chapter.In chapter three, the micro absorption rate of band electron is analyzed and the damage transient process is described. Our study include two parts (1) quantum treatment of the laser absorption rate of conduction electrons (2)the description of the electron density and film optical properties transient process (3) the calculation of laser damage threshold for some common optical films.In chapter four, the problem of the laser standing wave damage in the optical films is discussed. A suggestion that use the gradient film to substitute the classical high reflectivity film is given. The problems of wavelength matching and the intensity of electric field are also analyzed.In chapter five, some conclusions from our study are listed.