Diffraction grating is the core part of spectrum instruments. To get a good performance of the instruments, different structure should be designed with different type of the grating. A spectrograph, which works in the spectrum range from 340 nm to 800 nm, was designed, whose the resolution is higher than 15nm, and the dispersion size is 28.71 mm on the focal plane. According to comparison of structure of the common spectrographs, the flat field holographic concave grating structure with many advantages was chosen. The long pass filter was used to constrain the secondary spectrum, and the optical source was also considered. As a result, the resolution of the whole system is better than 10 nm, and the size is only 190 mm× 15 mm×60 mm. The flat concave-grating can be got from the market, which greatly decreases the cost of the product. Besides, only a grating can act as the spectrometer system, which can make the system easily assembly and very convenient for mass production.%光栅作为小型光谱仪器分光系统的核心,采用不同种类的光栅制作分光仪器时其结构形式也不尽相同.文中为设计一个工作波段在340-800 nm,分辨率优于15nm,谱面长度28.71 mm的比色仪光学系统,通过对比常见光谱仪结构的优缺点,选择平场凹面光栅作为最终的结构形式,采用长波通滤光片实现对二级光谱重叠的消除,并对比色仪光源系统进行设计,平场凹面光栅光学系统分辨率优于10nm,全系统大小约为190 mm×15 mm×60 mm的光学装置,平场凹面光栅采用市场现有的光栅.不仅满足设计要求,而且元件较少,有利于装调和批量化生产.
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