Study On The Laser Induced Damage Of Optical Films

With the development of laser technology, the research of interaction of laser and optical system becomes more and more important. As the essential basic component of almost all optical components, optical film is the most fragile. Thus, it is very significant to research the damage mechanism of optical film and improve laser induced damage threshold (LIDT).The interaction of laser and film materials is analyzed and the laser damage mechanism of optical films is roundly introduced in microcosmic and macroscopic aspects in this paper. Some influence factors of LIDT are introduced and some advices of improving LIDT are given .Based on thermal conduction theory,the physical model of the temperature field of multiplayer films illuminated by Gaussian laser is built. The numerical calculation program is built up by using alternating direction-implicit technique and confirmed by the calculating results of the Stanford University, showing the validity and credibility. On that basis,temperature field of several conditions and material film is simulated and analyzed. The application of finite element method (FEM) in thermal conduction is introduced. Transient temperature field of Al2O3 film based on K9 as substrate is simulated by using FEM software ANSYS.The results obtained in this thesis would be of both theoretical significance and practical interest in the fabrication of thin films.