文档介绍：光光光谱谱谱光光光栅栅栅仪仪仪中中中高高高精精精度度度快快快速速速波波波长长长扫扫扫描描描方方方法法法的的的研研研究究究
摘摘摘要要要
传统光栅扫描式光谱仪器由于机械结构的限制,无法达成高精度波长扫描
和高速扫描的统一。本论文针对传统的光栅光谱的扫描结构,设计了三种不同
的光栅光谱波长扫描方案来提高波长扫描系统的性能。
对于步进电机直接驱动光栅的结构,其扫描速度相比传统的丝杆结构有了
明显的提高,但在高细分状态下步进电机运行状态不稳定,造成整个波长扫
描系统的精度下降。在研究了步进电机和谐波电机的工作性能后,设计了采
用压电谐波电机直接驱动光栅的波长扫描方案。经过实验测试其波长准确度
为,波长重复性为。
为了进一步提高波长扫描的精度,通过对莫尔条纹技术的研究后,创新设
计了运用莫尔条纹光栅尺对光栅转动进行实时监控的扫描系统。该系统由步进
电机带动丝杆,丝杆滑块在带动光栅转动的同时带动光栅尺平移,通过莫尔条
纹技术测量滑块的平移量,并运用莫尔条纹的高精度的特点来反馈光栅的转动
情况,以提高系统的性能。经过测试,其波长准确度为,波长重复性
为。
运用光栅尺传感器的波长扫描系统虽然精度较高,但是成本也偏高。为
此,在研究了多边形棱柱反射镜的结构和工作原理后,设计了采用激光、位置
敏感探测器PSD以及底面为正多边形的旋转棱柱反射扫描镜的全新主动光电扫
描反馈光栅角度位置的结构和方法。经过测试,扫描波长准确度±,重
复性≤,扫描速度为20s/幅光谱。
三种方案中运用莫尔条纹技术和多边形棱柱镜的设计性能最佳,并且多边
形棱柱镜的结构相对于前者在成本上有大幅的降低。本论文为高精度光谱扫描
系统的设计和改进寻找了一些新的思路和方法。
关键词: 光栅光谱仪步进电机谐波电机莫尔条纹多边
形棱柱镜
— i —
Research on a quick and high accuracy wavelength setting
method for grating spectrometer
ABSTRACT
For the structure limit of traditional wavelength scanning systems based on screw
mandrel and step motor, they cannot simultaneously work both accurately and quickly.
Three new meatheads to improve the performance of classical wavelength scanning
system are proposed in this paper.
By the research on the step motor directly driven system, it is found that it spends
less time to scan a whole spectrum, but the step motor runs unsteadily in high subdivi-
sion mode, which will decrease the system’s wavelength accuracy. After studying the
performance of step motor and harmonic motor, a harmonic motor driven scanning
system is designed. As the step motor, the harmonic motor has better performance
on accuracy and stability. Test result shows that this system’s wavelength accuracy
reaches while the repeatability is .
In order to increase the system’s accuracy, a feed back structure is needed. So
a Moire fringe technique used system is designed, it is supposed to feed back the
scanning performance of the gating. The gating is driven