There is increasing use of mid-infrared optical parametric oscillator radiation operating in the wavelength range of 3–5 µm. To expand existing damage data for skin exposure to lasers in this wavelength region, the in-vivo damage threshold at the wavelength of 3.743 µm was determined in a Guizhou miniature pig model for an exposure duration of 1.0 s. The irradiance of the laser spot was nearly Gaussian-distributed and the 1/e² beam diameter on the animal skin surface was fixed at 0.94 and 0.88 cm along horizontal and vertical directions. Damage lesion determinations were performed at 1- and 24-hour post-exposure. The probit analysis was employed to establish the ED₅₀ values. The ED₅₀ expressed in peak radiant exposure for the Gaussian spot was 4.04 J/cm² at the 24-hour post-exposure. Sufficient margin existed between the damage threshold and MPE from the current laser safety standard. The obtained data may contribute to the knowledge base for refinement of laser safety standard in the wavelength range of 2.6–1000 µm.

中文翻译：

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中红外光学参量振荡器辐射对3.743 µm的猪肉造成的皮肤损伤阈值

在3-5 µm波长范围内工作的中红外光学参量振荡器辐射的使用正在增加。为了扩大现有皮肤在该波长范围内暴露于激光的损伤数据，在贵州小型猪模型中确定了波长为3.743 µm的体内损伤阈值，暴露时间为1.0 s。激光光斑的辐照度几乎是高斯分布的，并且动物皮肤表面上的1 / e ²光束直径沿水平和垂直方向固定为0.94和0.88 cm。暴露后1小时和24小时进行损伤损伤测定。概率分析用于确定ED ₅₀值。ED ₅₀暴露后24小时，高斯光斑的峰值辐射暴露表示为4.04 J / cm ²。根据当前的激光安全标准，在损伤阈值和MPE之间存在足够的余量。所获得的数据可能有助于完善2.6–1000 µm波长范围内的激光安全标准的知识库。