激光光梯度力消除雾霾的实验研究
Experimental Investigation for Eliminating Haze Particles by Laser Gradient Force

利用激光光梯度力破坏雾霾粒子的力平衡体系从而加速雾霾沉降的新机理,搭建了模拟动态雾霾的实验舱。通过向悬浮的雾霾粒子辐射激光的方式验证了激光消除雾霾的可行性。大气中的雾霾粒子由于受到曳引阻力、范德瓦尔斯斥力、旋转升力等的作用,处于稳定的网状力平衡状态。激光与雾霾粒子的相互作用过程即为利用激光光梯度力俘获电介质粒子的过程。当激光产生的光梯度力打破雾霾粒子所处的平衡状态时,激光对雾霾粒子的捕获能力大于大气的悬浮能力,雾霾粒子便会脱离原有的力平衡体系而坠落。实验数据表明,功率为2.6 mW的氦氖激光器产生的光梯度力足以打破直径分别为0.3、0.5和1.0 μm的雾霾粒子原有的力平衡体系。激光开启时,实验舱内粒子浓度急剧衰减,衰减速率明显高于粒子的自然衰减速率,成功达到了加速粒子沉降的目的。实验结果还表明,烟雾粒子粒径越大沉降的效果越明显。这种治理雾霾的新机理对净化大气、消除工厂粉尘以及对人们的健康生活、经济持续发展等具有重要意义。
Following the new mechanism of eliminating haze particles by optical gradient force, a test chamber for simulating dynamic haze is constructed. The feasibility of eliminating haze is verified by a laser beam irradiating suspended haze. The forces including air drag force, van der Waals repulsion force and rotary lift force keep the haze particles staying in a stable force balance status in the atmosphere. The interaction between laser and haze particles explains the process of optical gradient force trapping the dielectric particles. When the optical trapping force breaks the balance status of the haze particles, the haze particles are separated from the original force balance system then fall. The experimental results show that the optical gradient force generated by a 2.6 mW He？？Ne laser is sufficient to break the original force balance system of haze particles with diameter of 0.3, 0.5 or 1.0 μm. When laser is once applied, the concentration of haze particles declines rapidly, and the decay rate is much faster than the natural decay rate. Thus, the purpose of eliminating haze particles is successfully achieved. In addition, the close relationship between the particle size and elimination of haze is also discussed. It is undoubted that the proposed way of eliminating haze particles can effectively purify air and reduce factory dust to exhibit the great significance for both healthy life and sustainable economic development