Huang Huan, Yang Lih-Mei, Bai Shuang, Liu Jian
Appl Opt. 2015 Jan 10;54(2):324-33. doi: 10.1364/AO.54.000324.
This study presents an unprecedented high throughput processing for super-blackening and superhydrophobic/hydrophilic surface on both planar and nonplanar metals surfaces. By using a high pulse repetition rate femtosecond (fs) fiber laser, a light trapping microstructure and nanostructure is generated to absorb light from UV, visible to long-wave infrared spectral region. Different types of surface structures are produced with varying laser scanning conditions (scanning speed and pitch). The modified surface morphologies are characterized using scanning electron microscope and the blackening effect is investigated through spectral measurements. Spectral measurements show that the reflectance of the processed materials decreases sharply in a wide wavelength range and the decrease occurs at different rates for different scanning pitches and speeds. Above 98% absorption over the entire visible wavelength region and above 95% absorption over the near-infrared, middle-wave infrared and long-wave infrared regions range has been demonstrated for the surface structures, and the absorption for specific wavelengths can go above 99%. Furthermore, the processing efficiency of this fs fiber laser blackening technique is 1 order of magnitude higher than that of solid-state fs laser and 4 times higher than that of picosecond (ps) laser. Further increasing of the throughput is expected by using higher repetition and higher scanning speed. This technology offers the great potential in applications such as constructing sensitive detectors and sensors, solar energy absorber, and biomedicine.
本研究展示了一种前所未有的高通量处理方法，用于在平面和非平面金属表面实现超黑化以及超疏水/亲水表面。通过使用高脉冲重复率飞秒（fs）光纤激光器，可生成光捕获微结构和纳米结构，以吸收从紫外、可见光到长波红外光谱区域的光。在不同的激光扫描条件（扫描速度和间距）下会产生不同类型的表面结构。使用扫描电子显微镜对改性后的表面形貌进行表征，并通过光谱测量研究黑化效果。光谱测量表明，加工材料的反射率在很宽的波长范围内急剧下降，并且对于不同的扫描间距和速度，下降速率不同。对于这些表面结构，已证明在整个可见波长区域吸收率超过98%，在近红外、中波红外和长波红外区域吸收率超过95%，并且特定波长的吸收率可超过99%。此外，这种飞秒光纤激光黑化技术的加工效率比固态飞秒激光高1个数量级，比皮秒（ps）激光高4倍。通过使用更高的重复频率和更高的扫描速度，有望进一步提高通量。该技术在构建灵敏探测器和传感器、太阳能吸收器以及生物医学等应用中具有巨大潜力。
