Structural Stability Of Large-scale Solid-state Laser Device, Optical Components Analysis

High-power solid-state laser technologies have been developed for applications to inertial confinement fusion (ICF) in the last few decades. Laser facilities have been built with the output energy of about a hundred Joules at the beginning up to a few mega-Joules now and beamline numbers have increased to hundreds. For such facilities, each beamline contains numerous optical elements with enlarged apertures of up to a few tens centimeters and the optical paths extend as long as hundreds of meters. When the laser facilities are in operation, the position and direction of all the beams are subject to change due to the optical structural drifts excited by multiple input sources. These changes will influence the precision of the beam propagation and finally the focal spot positions on targets which are strictly dictated by the requirements of plasma physics experiments. Therefore, special attentions have been paid to study the stability of optical components and their mechanical structures. In the light of complex for high-power solid-state laser, the mechanism and relations of optical component stability and target positioning precision ,as well as excitation sources have been analyzed and studied. The model of allocating the stability specifications of optical components has been set Up. As the results, the following progresses have been made:1. The relation between drifts of optical components and the beam focal positions on targets has been analyzed and a physical model has been set up to describe the relation.2. A mathematic model of multi-object optimization about the stability allocation criteria of optical components has been set up. The linear sum-weight and probability theory are introduced to solve the mathematic model and to budget the stability of the function blocks and the optical components.3. A raytrace model of both co-axis and non-axis beam propagations for high-power solid-state laser systems has been set up and simulations on shots have been conducted to get the spot distribution at target point. According to the requirement of system design and theory of mathematic statistics, the dispersion circle and frequency distribution, which optimize the stability allocation of optical components, have been presented.4. Based on AutoCAD platform , the code of the stability allocation of optical elements and optical path layout for application to SG-â…¢ and its prototype has been developed with ObjectARX 2000 and MFC . The table of SG-III prototype stability allocation is provided. Optical path layout of SG-III of target area is completed with the formats of data and graph.5. The excitation sources that can cause motion of the optical elements and its relations are studied and analyzed. Based on stability of optical component, the stability allocation theory and methodology for accounting for excitations are presented.