节点文献

宽波段平面光栅效率测试仪设计及测量误差补偿方法研究

Research on Design and Testing Error Compensation of Wide Spectral Coverage Test Instrument for Plane Grating Diffraction Efficiency

【作者】 曹海霞

【导师】 巴音贺希格;

【作者基本信息】 中国科学院研究生院(长春光学精密机械与物理研究所) , 光学, 2014, 博士

【摘要】 为了发展高光谱分辨率的光谱技术、开展高光谱遥感仪器原理样机等关键技术研究,形成具有大气成分监测的能力,2012年长春光机所承担了有效载荷高光谱与高空间分辨率大气CO2探测仪的研制工作。大气CO2探测仪采用大闪耀角大尺寸平面衍射光栅为核心元件进行设计。因为光栅的衍射效率影响仪器的能量传输能力,进而影响大气CO2浓度的检测精度及反演精度,因此需对大气CO2探测仪所采用的对大尺寸平面光栅的衍射效率进行测量,但是现有设备受测试波段范围及探测待测光栅尺寸的限制,无法实现大尺寸平面光栅衍射效率的测量;而且不能准确反应大尺寸平面光栅在CO2探测仪中工作状态下的能量传输性能。有相关报道称搭建光路,采用可调谐激光器作为光源,在待测光栅的空间表面选择几个点进行光栅效率的测量,但是这种方法不能实现待测光栅在实际工作状态下全口径效率的测量,因此无法全面衡量待测光栅的衍射效率。同时,测试仪出射狭缝的尺寸及探测器的感光面积也限制了待测元件出射光通量的接收。基于此,本文根据大气CO2探测仪对大尺寸平面光栅的需求,对宽波段平面光栅效率测试仪在光学设计、光栅效率测量方法及测量过程、测试仪的误差补偿方法及系统装调测控等进行了较为深入的研究。主要研究工作如下:第一,针对大气CO2探测仪对大尺寸平面光栅的需要及其实际工作状态,结合光栅效率测试原理,采用双单色仪的设计方法设计了宽波段平面光栅效率测试仪。为了满足宽波段的要求,提出前置单色仪采用分光光栅组的设计方式。根据实际光线追迹结果显示,宽波段平面光栅效率测试仪能够满足大尺寸平面光栅在大气CO2探测仪中工作状态下全口径效率的测量。第二,在现有探测器感光面积限制的情况下,提出采用能量积分的方法采集出射光通量,并实例验证此测量方法的正确性。同时,针对测量过程中遇到的实际问题,进行理论分析,确定待测元件的状态调整方法。第三,衍射效率测量值的精度受测量过程和补偿方法的影响,为使效率测量值的测量精度得到进一步提高,进一步考察了影响衍射效率测量精度的主要因素,并在此基础上推导出了适用于平面光栅的光束截面变化因子k(θ)的解析表达式,提出采用二次非线性回归分析的方法对测量结果进行补偿,将补偿过程嵌入测量程序,该方法能够实时补偿测量结果,满足仪器准确测量的要求。第四,通过对测试仪光学系统的光路结构及像差分析,提出采用光学元件精确装调与显微镜信号读取判别相互结合的宽波段平面光栅效率测试仪的装调方法,利用此方法实现了宽波段平面光栅效率测试仪的精确装调。同时,根据光栅效率的测量过程,开发了集效率测试仪前置单色仪波长标定及扫描、系统装调、测试、测量结果的误差补偿于一体的操作软件,为各种规格光栅效率的测试提供便利。

【Abstract】 In order to develop high spectral resolution spectroscopy and carry out the keytechnical research on prototype instruments of hyper-spectral remote sensing, thenget the ability of monitoring and testing the atmospheric composition,2012Changchun Institute of Optics, fine mechanics and physics take on the carbon starspayload of with CO2detector with high spatial and hyper spectral resolution.Atmospheric CO2detector introduces the large blaze angle reflection plane gratingas the core component. Diffraction efficiency of the grating play a decisive role tothe energy transfer capability of the instrument, thereby affecting the detectionaccuracy and precision of the inversion for CO2concentration of atmospheric CO2detector, so atmospheric CO2detector also made the target to its diffractionefficiency of the large-size flat grating, but the existing testing equipment bear therestriction of wavelength range and detection of the test grating size, cannot achievethe testing diffraction efficiency of large-size flat grating; Meanwhile, the testingvalue for large size of the grating in the existing equipment cannot accurately reflectthe energy transmission performance at its work state in atmospheric CO2detector.Related structures have reported that using a tunable laser as a light source, selectseveral points at the grating surface in the space to measure the grating diffraction efficiency, but this method cannot achieve the full aperture efficiency in the practiceworking condition, and therefore cannot fully measure the diffraction efficiency ofthe test grating. Meanwhile, the tester exit slit size and the detector sensitive areaalso limits the detecting of the flux of the testing element.Given these reasons, according to the requirement of CO2detecting instrument tothe large-scale plane grating, we deeply study the instrument in these aspects, whichincluding the optical system design, the optics assembly method, the efficiencymeasurement method and the error compensation method. The chief research workon the instrument is as following. Firstly, in allusion to the working condition andthe requirement of large-size grating, according to the principle of grating efficiencymeasurement, adopting the structure of double-monochromator to design theinstrument. For the requirement of wide spectral coverage, we put forward thedesign of the pre-monochromator gratings group. According to the actual result ofray tracing, we know that the wide spectral coverage diffraction efficiencyinstrument can satisfy the efficiency measurements of large size plane grating.Secondly, because the existing detector photosensitive area is restricted, bring on theenergy integral method to collect the exit flux, and validate the correctness of themeasurement method. At the same time, in view of the practical problems, weanalyze them theoretically according to the principle of measuring grating efficiency,and determine the adjustment method of optical elements. Thirdly, the gratingefficiency obtained from the instrument is a relative value, and the measuringaccuracy of its value is affected by the measurement process and the compensationmethod. To improve the measuring accuracy of the grating efficiency, this paperfurther investigates the main factors influencing the measurement accuracy, deducethe analytic expression for the change factor of beam cross section (k(θ)). And thenput forward the compensation formula of improving efficiency measurementaccuracy. Through embedding the compensation procedures in the measuringsoftware, the method can get real-time results, and meet the requirement of theinstrument for accurate measurements. Fourthly, through the analysis of the performance of optical system, we put forward the alignment method, with whichthe optical element precision alignment and the detection signal identification of themicroscope can be combined. Using this method, we achieve a precise alignment forthe wide spectral plane grating diffraction efficiency instrument on the basis of thedouble monochromator. And then, according to the measurement process of gratingefficiency, the operating software is developed, which has the functions of thewavelengths calibration and scanning, the optical system alignment and testing, andthe error compensation of the results. And this software provides convenience forvarious kinds of grating efficiency test.

节点文献中: 

本文链接的文献网络图示:

本文的引文网络