Abbasi Hamed, Canbaz Ferda, Guzman Raphael, Cattin Philippe C, Zam Azhar
Biomedical Laser and Optics Group (BLOG), Department of Biomedical Engineering, University of Basel, CH-4123 Allschwil, Switzerland.
Department of Neurosurgery, University Hospital Basel, CH-4056 Basel, Switzerland.
Biomed Opt Express. 2020 Dec 17;12(1):444-461. doi: 10.1364/BOE.405825. eCollection 2021 Jan 1.
Minimally invasive laser surgeries that require the use of a flexible endoscope (flexiscope) could benefit from high-energy nanosecond laser pulses delivered through fibers for real-time tissue characterization and phenotyping. The damage threshold of the fiber's glass material limits the maximum amount of deliverable peak power. To transmit high-energy pulses without damaging the fiber material, large-diameter fibers are typically used, leading to a limited bending radius. Moreover, in a large-core fiber, self-focusing can damage the fiber even if the tip remains intact. In this work, we tested a fused-end fiber bundle combined with a beam shaper capable of delivering more than 20 MW (>100 mJ/5 ns). The fiber bundle was tested over more than eight hours of operation, with different bending radiuses down to 15 mm. The results demonstrate, to the best of our knowledge, the highest peak power delivered through a flexible fiber, for a frequency-doubled Q-switched Nd:YAG laser.
需要使用柔性内窥镜（可弯曲内窥镜）的微创激光手术，可受益于通过光纤传输的高能量纳秒激光脉冲，用于实时组织表征和表型分析。光纤玻璃材料的损伤阈值限制了可传输的最大峰值功率。为了在不损坏光纤材料的情况下传输高能量脉冲，通常使用大直径光纤，这导致弯曲半径受限。此外，在大芯光纤中，即使光纤尖端保持完好，自聚焦也可能损坏光纤。在这项工作中，我们测试了一种与光束整形器相结合的熔接端光纤束，该光束整形器能够传输超过20兆瓦（>100毫焦/5纳秒）的能量。该光纤束在超过八小时的运行时间内进行了测试，弯曲半径低至15毫米。据我们所知，结果表明，对于倍频调Q Nd:YAG激光，通过柔性光纤传输的峰值功率最高。
