便携式土壤重金属探测仪光学结构设计

Optical structure design of portable soil heavy metal detector

当前土壤中的重金属污染日益严重,研究开发便携式土壤重金属快速、现场检测技术设备能为土壤重金属污染状况普查提供快速、有效的技术手段。系统中发射光路采用透镜对激光光束会聚并作用到样品;收集光路采用抛物面镜组对等离子体光信号收集并耦合至光纤。分析了激光光束经透镜汇聚后作用到样品时的功率密度,给出了等离子体光信号耦合至光纤端面的光斑大小,并得到整个光学系统的大小尺寸。结果表明,整个光学系统结构紧凑、体积小、光信号耦合效率高,非常适用于便携式土壤重金属快速、现场的探测系统应用。

Currently, soil heavy metal pollution is getting increasingly serious. It can provide fast and efficacious method for the survey of soil heavy metal pollution in China to research and develop portable, fast and field soil heavy metal detection equipment. In the system a lens is used to focus the laser beam on the sample and a couple of paraboloidal mirrors are used to collect the plasma optical signal into the optical fiber. The power density of the laser beam which is focused on the sample is analyzed, the size of the light spot which is collected into the optical fiber end is given, and the size of the whole optcial system is gotten. The result shows that the light signal coupling efficiency is high and the struc- ture of the whole optical system is compact, small-size and suitable for fast, field soil heavy metal detection equipment.