Hot-images induced by the random distribution defects in high power laser systems

Based on the diffraction theory model of hot-images, the formation mechanism of the hot-images induced by the defects with random size and position distribution in a high power laser system is theoretically investigated by using the propagation matrix of the spatial spectrum. For the comparison with the theoretical results, the evolution of the hot-images induced by defects with random distribution is also numerically investigated. Furthermore, the relationship describing the tendency of the hot-image intensity with the number or size range of the defects is analyzed by employing statistical theory. The results show that the hot-image intensity will reach a maximum if the size of the corresponding defect approaches a specific value, and that there exists a corresponding relation between the transverse position of the hot-image point with the maximum intensity and the defect distribution. It is also found that the intensity of the hot-image has an upward trend with both the size range and the number of defects within a certain scope increasing. However, the tendency will be steady when the probability of the defects with the most risk of damage size reaches a certain value. Such results maybe provide a guidance for improving cleanliness of the optical components.