McCally Russell L, Bonney-Ray Jennifer, Bargeron C Brent
The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723-6099, USA.
Health Phys. 2004 Dec;87(6):615-24. doi: 10.1097/01.hp.0000137181.53428.04.
Corneal epithelial injury thresholds have been determined for exposures to 1.54 mum infrared radiation from an Erbium fiber laser. Thresholds were determined for beam diameters from 0.05 to 0.7 cm for exposures having durations from approximately 1 to 100 s and for a fixed beam diameter of 0.1 cm for exposures with durations between 0.036 and 0.26 s. Near-threshold damage appeared within 30 min post-exposure. There was no evidence of latent damage from lesser exposures appearing up to 24-48 h post-exposure. The dependence of the threshold radiant exposures on laser beam diameter for exposures >1 s provides strong evidence supporting a critical temperature damage model. However, the shorter exposures are not in accord with a critical temperature damage model. Thresholds for exposures longer than 1 s are greater than 10 times the maximum permissible exposure (MPE) in ANSI Z-136.5-2000; however, the safety factor decreases to less than 10 for exposures less than 0.1 s with a 0.1-cm-diameter beam.
已确定了暴露于铒光纤激光器发出的1.54微米红外辐射下的角膜上皮损伤阈值。对于持续时间约为1至100秒的暴露，确定了光束直径从0.05至0.7厘米时的阈值；对于持续时间在0.036至0.26秒之间的暴露，确定了固定光束直径为0.1厘米时的阈值。接近阈值的损伤在暴露后30分钟内出现。没有证据表明较小暴露量会在暴露后24至48小时内出现潜在损伤。对于持续时间大于1秒的暴露，阈值辐射暴露对激光束直径的依赖性提供了支持临界温度损伤模型的有力证据。然而，较短的暴露时间不符合临界温度损伤模型。持续时间超过1秒的暴露阈值大于ANSI Z - 136.5 - 2000中最大允许暴露量（MPE）的10倍；然而，对于直径为0.1厘米的光束，持续时间小于0.1秒的暴露，安全系数降至小于10。
