提出一种高斯光束照射下颗粒后向散射光信号的测试方法,对悬浮于流体中不同粒径的玻璃微珠进行了测量,并对测得的脉冲波形进行分析。结果发现,采集的波形基本上符合高斯分布,且波形峰值与粒径有较好的线性关系。对不同颗粒数浓度的粒径为19.2 μm的标准玻璃微珠的信号波形进行实时采集,得到了浓度与脉冲数的对应关系。研究结果表明,所提出的测试方法可以得到颗粒粒径和浓度信息,有望应用于后续激光放大器的腔内检测。

This study proposes a method to measure the backward scattered signals from particles illuminated by Gaussian beams. Micro-glass beads suspended in the fluid are measured, and the measured pulse waveforms are analyzed. Results reveal that the signal profile fits the Gaussian profile; the height of the Gaussian profile is approximately linear to the particle diameter. The standard glass beads with diameter of 19.2 μm are used to acquire signals under different number concentrations in real time, and the dependence of the pulse number on the particle concentration is obtained. Experimental results also confirm that the proposed method can measure both the particle size and concentration, thereby providing a basis for the measurement in the amplifier cavity of a laser system in the future.