Silica optical fibers are employed in endoscopy and related minimally invasive medical methods thanks to their good transparency and flexibility. Although silicon oxide is a biocompatible material, its use involves a serious health risk due to its fragility and the fact that potential fiber fragments can freely move inside the body without the possibility of being detected by conventional methods such as X-ray imaging. A possible solution to this issue can be the development of optical fibers based on bioresorbable (i.e., biodegradable and biocompatible) materials, which exhibit the important benefit of not having to be explanted after their functionality has expired. The optical power transmission tests of recently developed single-mode (SM) and multi-mode (MM) bioresorbable optical fibers based on calcium-phosphate glasses (CPGs) are here reported. A continuous-wave (CW) fiber laser at 1080 nm with output power up to 13 W and picosecond laser sources at 515 and 1030 nm with MW pulse peak power were used to test the transmission capabilities of the CPG fibers. No degradation of the CPG fibers transmission under long-term illumination by CW laser was observed. A laser-induced damage threshold (LIDT) at a fluence higher than 0.17 J/cm² was assessed with the picosecond laser sources.

中文翻译：

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磷酸钙基生物可吸收光纤的高功率激光测试

二氧化硅光纤因其良好的透明度和柔韧性而被用于内窥镜检查和相关的微创医疗方法。尽管氧化硅是一种生物相容性材料，但由于其易碎性以及潜在的纤维碎片可以在体内自由移动而无法通过 X 射线成像等常规方法检测到的事实，它的使用涉及严重的健康风险。这个问题的一个可能解决方案是开发基于生物可吸收（即生物可降解和生物相容）材料的光纤，其具有在其功能到期后无需移植的重要优势。本文报道了最近开发的基于磷酸钙玻璃 (CPG) 的单模 (SM) 和多模 (MM) 生物可吸收光纤的光功率传输测试。使用输出功率高达 13 W 的 1080 nm 连续波 (CW) 光纤激光器和具有 MW 脉冲峰值功率的 515 和 1030 nm 皮秒激光源来测试 CPG 光纤的传输能力。在 CW 激光的长期照射下，没有观察到 CPG 光纤传输的退化。能量密度高于 0.17 J/cm 时的激光诱导损伤阈值 (LIDT) 在 CW 激光的长期照射下，没有观察到 CPG 光纤传输的退化。能量密度高于 0.17 J/cm 时的激光诱导损伤阈值 (LIDT) 没有观察到 CW 激光长期照射下 CPG 光纤传输的退化。能量密度高于 0.17 J/cm 时的激光诱导损伤阈值 (LIDT)²是用皮秒激光源评估的。