High power erbium fibre laser for laser cleaning applications

激光清洗是一种高效、环保的非接触式方法，可去除人造结构中的油漆和不需要的表面污染，从而提高寿命、性能和外观，而不需要使用化学品、水或研磨机械工具。脉冲光纤激光器和基于Yb或Nd3+的固态激光器由于其功率调节优势，已成为激光清洗的首选激光器，目前有许多商业产品服务于这一市场。然而，这些激光器的缺点是，眼睛损伤开始之前的最大允许曝光量(MPE)限制相对较低，因此，激光清洁操作仅限于封闭环境。该项目将研究一种新的策略，用于定标光纤激光器，以满足激光清洗的需要，但在波长范围(~1.55-1.6um)内，MPE限制远高于~1um激光器的数量级。这将允许在户外情况下部署，而不需要外壳，从而允许在更广泛的情况下使用激光清洗。如果成功，这将给激光清洗带来革命性的变化，并开辟更多应用的前景，因为大大放松了安全考虑。在激光性能方面，目标将是开发一种激光功率缩放技术，该技术可以提供能量范围在~10-100MJ、持续时间&lt；50 ns、平均功率在几百瓦到千瓦范围内的脉冲输出，以满足预期应用的需要。

Laser cleaning is an efficient and environmentally-friendly non-contact method for removing paint and unwanted surface contamination from manmade structures to improve longevity, performance and appearance without the need for chemicals, water or abrasive mechanical tools. Owing to their power scaling advantages, pulsed fibre lasers and solid-state lasers based on ytterbium or neodymium have become the lasers of choice for laser cleaning and there are now a number of commercial products serving this market. However, these lasers suffer from the shortcoming that the maximum permissible exposure (MPE) limit before the onset of eye damage is relatively low and, as a consequence, laser cleaning operations are restricted to enclosed environments. This project will investigate a new strategy for scaling fibre lasers to meet the needs for laser cleaning, but in a wavelength band (~1.55 -1.6 um) where the MPE limit is well over an order-of-magnitude higher than for ~1 um lasers. This will allow deployment in outdoor scenarios, without the need for an enclosure, allowing laser cleaning to be used in a much wider range of situations. If successful, this will revolutionise laser cleaning and open up the prospect of even more applications made possible due to the greatly relaxed safety considerations. In terms of laser performance, the goal will be to develop a laser power scaling technology that can deliver pulsed output with energy in the range ~10-100 mJ, duration <50 ns and average powers in the few hundred-watt to kilowatt regime, as required for the intended applications.