Ghost image analysis of multi-pass amplifier laser

All of the light that reaches a position other than the intended position is referred as stray light. Stray light generated in multi-pass amplifier system forms a lot of ghost image, which not only seriously influence the laser beam quality and propagation properties, but also damage optical components, and is one of major risks that high power laser system operate regularly. Based on the basic principle of geometrical optics, the transmission of beam is analyzed, a ray tracing method of ghost analysis is mentioned, the mathematical and physical model for analysis of stray light and ghost images has been set up, the analysis software has been presented. Taken a simple system as example, these ghost images and the energy density of key components in the system is get correctly. The results are instructive to the actual work of multi-pass amplifier laser design.