Infrared laser damage thresholds for skin at wavelengths from 0.810 to 1.54 microns for femto-to-microsecond pulse durations
Infrared laser damage thresholds for skin at wavelengths from 0.810 to 1.54 microns for femto-to-microsecond pulse durations
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波长为 0.810 至 1.54 微米、飞秒至微秒脉冲持续时间的红外激光对皮肤的损伤阈值
DOI：
10.1117/12.715199
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发表时间：
2007
影响因子：
4.6
通讯作者：
B. Rockwell
中科院分区：
文献类型：
--
作者：
C. Cain;W. Roach;D. Stolarski;G. Noojin;S. Kumru;K. Stockton;J. Zohner;B. Rockwell
在本文中，我们报告了我们对猪皮可见光损伤阈值的联合测量，波长从1010nm在44fs到1318nm，脉冲持续时间为50ns和350ms；S至1540 nm，包括31 ns和600 &mgr； S的脉冲持续时间。我们还测量了从直径小于1毫米到5毫米的各种光斑尺寸的阈值。所有三种波长和五个脉冲持续时间广泛用于研究和军事。我们将这些最小可见损伤阈值与ANSI标准设置的最大允许暴露在红外波长中进行比较。我们已经测量了脉冲持续时间低于1&mgr时激光组织界面的非线性效应；S，并确定这些短脉冲持续时间的损伤通常不是热效应。皮肤表面的损伤可能包括声学效应、激光消融和/或低密度等离子体效应，这取决于波长和脉冲持续时间。此外，这种损害可能是短暂的，几天内就会消失，也可能持续更长的时间，包括永久性变色。对于810 nm的飞秒脉冲，损伤几乎是瞬间发生的，在1小时内脉冲能量的ED50为8.2 mJ。24小时后，大部分病变消失，ED50几乎增加了3至21.3 mJ。1.318 &mgr；激光光斑尺寸为2mm和5mm，其中ED50在24小时后更大。然而，对于1.54 &mgr；光斑尺寸为5 mm的激光器，ED50实际上有少量下降；24小时后从6.3 Jcm-2到6.1 Jcm-2。1314 nm激光在350 &mgr时阈值也降低了；24小时后，0.7 mm和1.3 mm直径的光斑尺寸为S。在600 &mgr的1540 nm激光器中得到了不同的结果；当光斑直径为1 mm及以下时，ED50减小，而当光斑直径为5 mm时，ED50从6.4 Jcm-2略微增加到7.4 Jcm-2
In this paper we report on our combined measurements of the visible lesion thresholds for porcine skin for wavelengths in the infrared from 810 nm at 44 fs to 1318 nm at pulse durations of 50 ns and 350&mgr;s to 1540 nm including pulse durations of 31 ns and 600 &mgr;s. We also measure thresholds for various spot sizes from less than 1 mm to 5 mm in diameter. All three wavelengths and five pulse durations are used extensively in research and the military. We compare these minimum visible lesion thresholds with ANSI standards set for maximum permissible exposures in the infrared wavelengths. We have measured non-linear effects at the laser-tissue interface for pulse durations below 1&mgr;s and determined that damage at these short pulse durations are usually not thermal effects. Damage at the skin surface may include acoustical effects, laser ablation and/or low-density plasma effects, depending on the wavelength and pulse duration. Also the damage effects may be short-lived and disappear within a few days or may last for much longer time periods including permanent discolorations. For femtosecond pulses at 810 nm, damage was almost instant and at 1 hour had an ED50 of 8.2 mJ of pulse energy. After 24 hours, most of the lesions disappeared and the ED50 increased by almost a factor of 3 to 21.3 mJ. There was a similar trend for the 1.318 &mgr; laser for spot sizes of 2 mm and 5 mm where the ED50 was larger after 24 hours. However, for the 1.54 &mgr; laser with a spot size of 5 mm, the ED50 actually decreased by a small amount; from 6.3 Jcm-2 to 6.1 Jcm-2 after 24 hours. Thresholds also decreased for the 1314 nm laser at 350 &mgr;s for spot sizes of 0.7 mm and 1.3 mm diameter after 24 hours. Different results were obtained for the 1540 nm laser at 600 &mgr;s pulse durations where the ED50 decreased for spot sizes 1 mm and below, but increased slightly for the 5 mm diameter spot size from 6.4 Jcm-2 to 7.4 Jcm-2