Research Of Online Inspection Equipment For Optic Damage Of High Power Solid Laser

In the study of the high power solid laser for ICF (Inertial Confinement Fusion), online inspection for optic damage plays an important part in the research of high laser physics and technology. Damage inspection of the large aperture components is required for several reasons to minimize the risk to personnel and to reduce the risk to equipment due to an implosion of vacuum loaded optics, to reduce the performance degradation of the laser, and to provide the ability to remove optics before they are damaged beyond repair.Optics damage is mainly caused by the nonlinear effect of high laser, the damage of large optics includes the surface damage dots, interior focalized filaments, dust, scratches and so on. It is necessary for us to detect and know the damage when the size of the damage has gotten to the size of 1mm. Usually, the high power solid laser is designed to the optics system which contains Spatial Filter and more-pass cavity with amplifier. However, the online inspection system for optic damage is usually designed in miniature for the aperture of the beam is reduced. So we need study the following problems: the image of the damage overlapped each other, the problem of processing image and the resolution of the inspection system. The contents are mainly divided into six sections as follows:(1) The principle beam line of online inspection equipment is determined. Two ways for light how to detect the damage are considered, one is the transmission way and the other is reflected way, the theory analysis and experiment of two ways are studied. Considering the polarization and the energy of probe beam in the reflected way, the transmission way is the choice for the online inspection.(2) The imaging way of online inspection is also determined. By the comparison of the experiment conclusion of bright filed image and dark filed image, the imaging way is the way of the combination of two ways, which is the best way for online inspection.(3) The problem of overlapping image which is the result of more-pass cavity with amplifier and the depth of filed is solved. The optical schematic of the beam line is unfolded and Spatial Filter cavities are combined by different ways to separate image of damage. In order to solve the problem of depth of filed, the damage is determined at landscape orientation, and then to know more details at portrait.(4) The problem of image processing for online inspection is also solved. The image of damage is analyzed. Then the way suited to online inspection is put forward. And also the damage images are separated through image processing and different combination of spatial filter cavities.(5) The software of image processing for online inspection is designed. It includes the function of analysis, calculation, estimation and statistic of damage.(6) The elementary scheme of the equipment of the online inspection is determined. The online inspection simulation on the Final optics is carried through and the experiment is studied. Also, the simulation of SG-â…¢prototype laser is carried through and the elementary scheme is given out.