The Ohio State University, Laboratory for Multiscale Processing and Characterization, 1248 Arthur E. Adams Drive, Columbus, Ohio 43210, USA.
J Biomed Opt. 2009 Nov-Dec;14(6):064021. doi: 10.1117/1.3268444.
We investigated fabrication of cylindrical micropillars on bovine cortical bone using direct-write femtosecond laser ablation. The ablation threshold of the material was measured by single-pulse ablation tests, and the incubation coefficient was measured from linear scanned ablation tests. A motion system was programmed to apply multiple layers of concentric rings of pulses to machine pillars of various diameters and heights. The diameter of the top surface of the pillar was found to steadily decrease due to incubation of damage from successive layers of pulses during the machining process. Pillar top diameter was predicted based on a paraxial beam fluence approximation and single-pulse ablation threshold and incubation coefficient measurements. Pillar diameters predicted as successive layers of pulses were applied were well-matched to experiments, confirming that femtosecond laser ablation of the cortical bone was well-modeled by single-pulse ablation threshold measurements and an incubation coefficient.
我们研究了使用直接写入飞秒激光烧蚀在牛颅骨上制造圆柱形微柱的方法。通过单次脉冲烧蚀测试测量了材料的烧蚀阈值，通过线性扫描烧蚀测试测量了潜伏期系数。编程运动系统将多层同心脉冲环施加到各种直径和高度的柱子上。在加工过程中，由于连续层脉冲的损伤潜伏期，发现柱子的顶面直径逐渐减小。根据傍轴光束强度近似值和单次脉冲烧蚀阈值以及潜伏期系数测量值，预测了柱子的顶面直径。当施加连续层脉冲时，预测的柱子直径与实验非常吻合，这证实了皮质骨的飞秒激光烧蚀可以通过单次脉冲烧蚀阈值测量和潜伏期系数很好地建模。
