Hot Images from Obscurations

Evolution of the hot image effect in high-power laser system with cascaded Kerr medium

“…This tendency is consistent with the conclusions in Ref. [1]. By changing the distance d 1 and the interval L properly, the hot image spots appear alternatively as shown in Fig.…”

“…A surprising phenomenon was also found that the damage spots appeared alternatively in a system structured by cascaded medium (such as equispaced Kerr medium plates arrayed as the Brewster's angle). Since Hunt et al [1] firstly revealed the formation mechanism of the hot image in 1993, hot image effect has aroused widely interests in the high-power laser community [2][3][4][5][6][7][8]. A theoretical analysis method based on diffraction theory and thin-sheet approximation has been established.…”

“…Based on the thin-sheet approximation, Hunt et al gave some analysis on the peak intensity of the hot image in a cascaded medium system without gain and loss by using the matrix theory of wave propagation [1]. Wang et al also gave a theoretical analysis in a system structured by cascaded medium without gain and loss [8].…”

Study on impact of spatial filter on a hot image through medium with gain

“…The peak intensity of hot image may be several times larger than the initial background beam, What's worse, costly optics may be damaged if intensities of hot image exceed damage threshold of materials even the anticipated average fluences should have been at the safe operation point. The physical mechanism exposing the formation of the hot image [1] is first demonstrated by Hunt et al afterwards many researches on the character of hot image is constantly pursued. Widmayer et al [2,3] successively provided the nonlinear formation of images of obscuration and phase errors experimentally, and the computer model is proved to be in good agreement with experimental results.…”

<title>Laser-induced damage of fused silica at 355 and 1064 nm initiated at aluminum contamination particles on the surface</title>

“…The study was performed for contamination on both input and output surfaces of the silica window. In order to control the size and shape of the contamination particles, 1 µm thick Al dots of sizes ranging from 10 µm to 250 µm were sputter-deposited onto the silica; the 250 µm maximum contamination size was chosen since calculations showed that obscurations larger than 280 µm would not be tolerable (because of potential down-stream propagation) 17 but the effect of smaller particles on laser-induced damage was not known. Pure Al shavings deposited onto the silica were also irradiated.…”