电热式微机电系统微镜傅里叶变换红外光谱仪

为了研制小体积、低成本、高分辨率的微型傅里叶变换红外光谱仪,通过选择电热式微机电系统(MEMS)微镜作为迈克尔逊干涉仪动镜,在满足了傅里叶光谱仪小型化、便携化的同时,利用折叠双S型Bimorph驱动结构来实现双倍位移量以确保较高分辨率,并将分束器外置来进行不同波段的灵活选择,进而实现全光谱范围的应用。以1 310 nm激光作为参考光光源,钨灯宽带光作为待测光源信号,通过信号采集、滤波、插值、光谱恢复步骤完成原始信号采集到光谱信号复原的过程。测试结果表明:电热式微镜的位移量可达到500 m,光谱理论分辨率1 nm,光谱仪整机尺寸小至62 mm62 mm28 mm。测试基线噪声为0.000 04,基线重复性为0.000 32,吸光度重复性为0.000 48。性能指标能满足食品安全、药品检测、石油化工等领域的光谱检测应用。

Fourier transform infrared spectrometer based on electro-thermal MEMS micro-mirror

In order to develop the small, low-cost, high-resolution spectrometer, a miniaturization Fourier transform infrared spectrometer was design. By selecting electro-thermal MEMS micro-mirror as the moving mirror of Michelson interferometer to make the Fourier spectrometer miniaturization and portability. At the same time, to ensure a higher resolution, the folding double S Bimorph drive structure of double displacements was designed. The beam splitter was external for selection different wave band flexibly to achieve full spectrum range. Moreover, it used 1 310 nm laser as a reference light source, and tungsten lamp as interference light signal, through the signal acquisition, filtering, interpolation and spectrum recovery steps to complete that signal collected and absorption spectra recovery process. The results show that the displacement of electro-thermal micro-mirror can reach 500 m, and the theoretical resolution of the spectrum can be up to 1 nm, and the spectrometer machine size as small as 62 mm62 mm28 mm. Also the test results show that the baseline noise is 0.000 04, the repeatability of baseline is 0.000 32 and repeatability of absorbance is 0.000 48. The performance can meet spectrum detection applications of the food safety, drug testing, petrochemical and other fields.