应用光谱重建理论的傅里叶变换光谱仪

Fourier Transform Spectrometer Using Spectral Reconstruction Theory

本文将重建光谱仪的光谱重建理论应用于傅里叶变换光谱仪中,使光谱仪可以兼具重建光谱仪高光谱分辨率优势以及傅里叶变换光谱仪固有的高光通量优势。利用构建的简易空间外差傅里叶变换光谱仪实验装置在520~530 nm光谱范围内进行验证实验。使用实验装置采集的不同单波长入射光光斑图像进行光谱校准实验,证明了傅里叶变换光谱仪可满足光谱重建理论必需的光斑与波长间唯一的一对一映射关系。随后,使用用于光谱校准的光斑图像进行光谱重建实验,实现了0.10 nm的光谱分辨率,相比通过傅里叶变换光谱仪原理得到的~5.65 nm光谱分辨率有明显提高。最后,使用额外采集的波长525 nm入射光光斑图像进行光谱重建实验,重建光谱中存在重建误差,且525 nm处光谱信号峰的半峰全宽(FWHM)~0.30 nm。光斑图像相关性分析显示,光谱重建受光斑图像采集过程中噪声和相邻波长入射光光斑图像高相似性的影响。尽管如此,重建光谱仍然可以反映入射光的光谱信息,且信号峰的FWHM小于傅里叶变换光谱仪原理得到的光谱,验证了将光谱重建理论应用于傅里叶变换光谱仪的可行性和高光谱分辨率优势。

The spectral reconstruction theory of the reconstructive spectrometer is applied to the Fourier transform spectrometer.The method takes advantage of the high spectral resolution of the reconstructive spectrometer and the inherent high incident optical throughput of the Fourier transform spectrometer.Verification experiments were performed in the wavelength range of 520‒530 nm with a simple structured experimental setup of a spatial heterodyne Fourier transform spectrometer.We used the collected pattern images of input beams with different single wavelengths for spectral calibration experiments.The spectrometer can realize unique onetoone mapping between the patterns and wavelengths required by the spectral reconstruction theory.Spectral reconstruction using the spectral calibration patterns realizes a spectral resolution of 0.10 nm,a considerable improvement from~5.65 nm obtained using the Fourier transform spectrometer principle.Finally,an additional pattern image of the beam with a 525 nm wavelength was used in the spectral reconstruction experiment.The reconstructed spectrum contains reconstruction errors,and the full width at half maximum(FWHM)of the spectral signal peak is~0.30 nm.The correlation analysis of the pattern images shows that spectral reconstruction is affected by noise during pattern image collection and the high similarity of the pattern images of the incident beams of adjacent wavelengths.Nevertheless,the reconstructed spectrum reveals the spectral information of the incident light.Moreover,the smaller FWHM spectral signal peak than that obtained by the Fourier transform spectrometer verifies the feasibility and the advantage of high spectral resolution of applying the spectral reconstruction theory to the Fourier transform spectrometer.