光学学报, 2016, 36 (11): 1130002, 网络出版: 2016-11-08
微小型傅里叶变换光谱仪光场分析与衍射抑制
Optical Field Analysis and Diffraction Restraint of Microminiature Fourier Transform Spectrometer
摘要
为了进一步实现傅里叶变换红外光谱仪的微小型化,在基于多级微反射镜的傅里叶变换红外光谱仪结构中引入空间光调制器与点探测器。利用多级微反射镜对入射光场进行相位调制,同时利用空间光调制器对各干涉级次进行分布式测量。将两个多级微反射镜作为两个相位衍射屏并将空间光调制器作为振幅衍射屏,分析光波与每一个衍射屏的作用,发现干涉光场受到空间光调制器和多级微反射镜边缘衍射光场的调制。多级微反射镜边缘对入射光的截止产生了衍射效应,为了抑制该衍射效应对系统的影响,提出了一种扩展多级微反射镜阶梯级数的方法。该方法通过扩大干涉区域,避免了边缘衍射效应对内部有效干涉级次的影响。计算表明,该方法可以消除干涉图序列的失真,有效实现信号光谱复原。
Abstract
In order to further realize the miniaturization of the Fourier transform infrared spectrometer, a spatial light modulator and a point detector are introduced in the Fourier transform infrared spectrometer which is based on multistep micro-mirror. The phase of incident optical field is modulated by the multistep micro-mirror, and the distributed measurement is conducted for each interference order using the spatial light modulator. The two multistep micro-mirrors are regarded as two phase diffraction screens, and the spatial light modulator is regarded as an amplitude diffraction screen. The interaction between optical wave and each diffraction screen is analyzed. It is found that the interference optical field is modulated by the spatial light modulator and the diffraction optical field at the multistep micro-mirror margin. The incident optical field is cut off by the multistep micro-mirror margin, which results in the diffraction effect. In order to inhibit the influence of diffraction effect on the system, a method which extends the step order of the multistep micro-mirror is proposed. By means of enlarging the interference area, the influence of the marginal diffraction effect on the internal effective interference order can be avoided. The results indicate that this method can eliminate distortion of the interferogram sequence and achieve signal spectrum recovery effectively.
吕金光, 梁静秋, 梁中翥, 秦余欣. 微小型傅里叶变换光谱仪光场分析与衍射抑制[J]. 光学学报, 2016, 36(11): 1130002. Lü Jinguang, Liang Jingqiu, Liang Zhongzhu, Qin Yuxin. Optical Field Analysis and Diffraction Restraint of Microminiature Fourier Transform Spectrometer[J]. Acta Optica Sinica, 2016, 36(11): 1130002.