数字微镜器件(Digital Micromirror Device, DMD)作为一种新型的空间光调制器, 具有分辨率高、生产成本低、加工效率高等优点, 使用起来非常灵活, 因此实验室搭建了基于DMD的近红外光谱仪。首先, 介绍了DMD近红外光谱仪的基本工作原理。其次, 对该光谱仪进行了波长标定, 提出基于同一样品吸光度曲线相关系数的方法对其进行了波长台间差标准化, 使得波长的台间差在理论上小于0.1 nm, 在模型转移时符合要求。又通过在强光与弱光条件下对其噪声与信噪比的测试实验对比得出DMD近红外光谱仪不同编码模版的选择准则: 在强光条件下扫描方法优于阿达玛方法, 在弱光条件下相反。最后, 利用该光谱仪对实际样品汽油和柴油进行检测, 测试结果表明该光谱仪性能稳定。该DMD近红外光谱仪检测波长范围为1 330~2 500 nm, 吸光度偏差小于等于0.000 4 AU。

As a new type of spatial light modulator, Digital Micromirror Device(DMD) has the advantages of high resolution, low production cost and high processing efficiency. It is very flexible to use, so the laboratory built a near infrared spectrometer based on DMD. First, the basic working principle of DMD near-infrared spectrometer was introduced. Secondly, the wavelength of spectrometer was calibrated, a method based on the correlation coefficient of the same sample absorbance curve was proposed to normalize the inter-wavelength difference, so that the inter-station difference of the wavelength was theoretically less than 0.1 nm, which meet the requirements when the model was transferred. The selection criteria of different coding templates for DMD near-infrared spectrometer were obtained by comparing the noise and signal-to-noise ratio test under strong light and weak light conditions: the scanning method was better than the Hadamard method under strong light conditions, the opposite in weak light. Finally, the actual sample gasoline and diesel were tested by the spectrometer, and the test results showed that the spectrometer performance was stable. The near-infrared spectrometer based on DMD has a detection wavelength range of 1 330 to 2 500 nm, absorbance deviation is less than 0.000 4 AU.