分布式多光谱高温计光学系统设计

Distributed Design of Optical System for Multi-Spectral Temperature Pyrometer

多光谱辐射测温技术具有不干扰被测场、测量无上限以及响应速度快等优点,是高温测量领域的最有力工具之一。目前,多光谱高温计以点温测量为主,光路通过物镜、光阑、棱镜等光路通道将待测点辐射分光后进入探测器阵列,实现单点的多光谱信息采集。随着工业智能化程度的不断提高,更加需要实时获得大量的温度分布信息,如特种金属材料的冶炼过程、高温合金激光自动焊接过程、半导体晶体生长过程、火箭发动机尾喷焰温度诊断等领域都需要实时获得某条线乃至整个二维表面的温度,从而提高产品性能和质量,因此通过多光谱辐射测温技术测量待测表面某条线的温度分布十分重要。但是,简单将光阑变为狭缝,实现待测线表面的辐射经透镜、棱镜等传统光路分光后,由于光学系统球差的作用,会使得分光后的狭缝光谱由于离轴传输而呈现严重的弯曲现象,不利于矩形光电探测器阵列的完全接收。为此,提出基于正交柱状透镜组的多光谱线温光路系统,利用正交柱状透镜在不同位置成像可以实现由圆到椭圆再到直线的特殊作用,较好地解决了传统多光谱辐射高温计光路所存在的球差问题。利用ZEMAX光学设计软件,基于S4111-16Q的光电探测器阵列实际大小进行反向光学系统设计,确定了狭缝、物镜、棱镜、正交柱状透镜等光学器件关键的参数,基于这些参数所实际加工的光学器件,搭建了多光谱线温高温计光学系统,并进行了无正交柱状透镜和有正交柱状透镜成像情况下的对比实验,结果表明,在没有柱状透镜的情况下,狭缝成像明显弯曲,在加入正交柱状透镜的情况下,狭缝成像弯曲现象消失,经狭缝分光后的线光谱明显呈直线状态,这为整条线的光谱辐射信息完整进入各探测器阵列提供了技术支撑,从而为后续线温测量提供了有力的光谱辐射数据信息。

Multi-spectral radiation temperature measurement technology is one of the most powerful tools in high-temperature measurement because of its advantages of no interference to the measured field,no upper limit of measurement and fast response speed.At present,the multi-spectral pyrometer mainly measures point temperature.The optical path radiates the point to be measured through the objective lens,diaphragm,prism and other optical paths and then enters the detector array to realize the multi-spectral information collection at a single point.As industrial intelligence degrees unceasing enhancement,more need to obtain real-time information,a large number of temperatures of special metal materials such as the smelting process,high-temperature alloy laser automatic welding process,the semiconductor crystal growth process,the rocket launch the tail jet flame temperature diagnosis in areas such as all need to obtain real-time and even the entire two-dimensional temperature on the surface of a line,to improve product performance and quality.Therefore,it is very important to measure the temperature distribution of a line on the surface by multi-spectral radiometry.However,when the aperture is changed into a slit to realize the radiation splitting on the surface of the line to be measured through the traditional optical path such as lens and prism,the spectrum of the slit will be severely bent due to off-axis transmission due to the spherical aberration of the optical system,which is not good for the complete reception of the rectangular photoelectric detector array.Therefore,a multi-spectral line temperature and light path system based on an orthogonal cylindrical lens group is proposed in this paper.The special function from the circle to ellipse and straight line can be realized by using the orthogonal cylindrical lens in different positions,which better solves the spherical aberration problem existing in the light path of traditional multi-spectral radiation pyrometer.Using ZEMAX optical design software,the reverse optical system is designed based on the size of the s4111-16Q photodetector array.The parameters of key optical devices such as slit,objective lens,prism and orthogonal cylindrical lenses are determined.Based on the actual optical devices processed by these parameters,the optical system of multi-spectral line temperature pyrometer is built.The results show that the image of the slit is obviously bent without the orthogonal cylindrical lens,and the image of the slit is obviously bent without the orthogonal cylindrical lens,and the image of the slit is straight when the orthogonal cylindrical lens is added.It provides technical support for the spectral radiation information of the whole line to be integrated into each detector array,thus providing powerful spectral radiation data information for subsequent line temperature measurement.