基于火焰检测的紫外光学系统设计  

Design of UV optical systems based on flame detection

作　　者：丁天宇 雷改惠 曾智龙 葛孝心 王凤 DING Tianyu;LEI Gaihui;ZENG Zhilong;GE Xiaoxin;WANG Feng(School of Physics and Optoelectronic Engineering,Nanjing University of Information Science and Technology,Nanjing 210044,China;School of Electrical Engineering and Automation,Hubei Normal University,Huangshi 435002,China)

机构地区：[1]南京信息工程大学物理与光电工程学院,江苏南京410044 [2]湖北师范大学电气工程与自动化学院,湖北黄石435002

出　　处：《光学技术》2022年第6期653-657,共5页Optical Technique

基　　金：国家自然科学基金(12004188,62175113);江苏省重点研发计划(BE2022076)。

摘　　要：燃烧会产生黑体辐射和自由基辐射。为了获取火焰燃烧时产生的紫外辐射信息,设计了一个基于火焰光谱信息检测需要的紫外光学系统。增大了紫外光学系统工作带宽,改进长焦光学系统常规视场范围,使得该系统兼具宽谱段﹑大相对孔径﹑相对大视场和高分辨率等特点,提高了紫外光学系统成像质量,以便在较大范围内获取较为精准的火焰紫外光谱信息,从而获取火焰燃料成分等火焰基本信息,提升紫外光学系统适用性。系统工作波长范围为240~390nm,工作带宽较宽,系统F数为2.5,相对孔径较大,视场角为15°,全系统共十片透镜组成,总长小于170mm,结构紧凑,满足燃烧探测的所有基本需求。像质评价结果显示,系统各个视场像点弥散斑均方根半径均小于9μm,全波长范围内系统垂轴色差小于1个像素大小,同时调制传递函数值在截止频率50(lp·mm^(-1))处优于0.5,系统畸变不超过0.5%。设计结果表明,紫外光学系统具有成像性能优良,工作带宽较宽,色差小,分辨率高,畸变小等优点,与此同时系统所有透镜均为球面透镜,便于加工与检测,满足设计要求。Combustion produces blackbody radiation and free radical radiation.In order to obtain the ultraviolet radiation information produced by flame combustion,an UV optical system based on the needs of flame spectral information detection was designed.The design increases the working bandwidth of the ultraviolet optical system and improves the conventional field of view of the telephoto optical system.The system combines the characteristics of wide spectrum,large relative aperture,relatively large field of view and high resolution,so as to obtain more accurate flame ultraviolet spectral information in a large range.Thus the basic flame information such as flame fuel composition can be obtained and improve the applicability of the UV system.The operating wavelength of the system ranges from 240 nm to 390 nm,and the operating bandwidth is wide.The F-number of the system is 2.5,the relative aperture is large,and the field Angle of view is 15°.The whole system is composed of ten lenses,the total length is less than 170 mm,and the compact structure meets all the basic requirements of combustion detection.The image quality evaluation results show that the root mean square radius of the dispersion spots in each field of view of the system is less than 9μm,the maximum lateral color aberration of the system is less than one pixel in the full wavelength range,the value of the modulation transfer function(MTF) is better than 0.5 at the cut off frequency of 50(lp·mm^(-1)),and the system distortion is less than 0.5%.The design results show that the ultraviolet optical system has the advantages of excellent imaging performance,wide working bandwidth,small chromatic aberration,high resolution,and small distortion,etc.At the same time all the lenses of the system are the spherical lenses,which is convenient for processing and detection,and meets the design requirements.

关 键 词：火焰检测 光学系统设计 宽工作带宽 大视场 分辨率高 畸变小 

分 类 号：O439[机械工程—光学工程]