Lin Jun, Shao Jun, Song Chao-yu, Li Yun-wei, Lei Yu-fei
Guang Pu Xue Yu Guang Pu Fen Xi. 2015 Dec;35(12):3534-7.
The Fourier interferometric spectrometer (FIS) acquires the interference data information of the spectrum and during the spectrum data processing, a series of spectrum reconstruction will be performed on the interference information to obtain the final spectrum information data. The spectral calibration is the key step to spectrum reconstruction of FIS, which directly determines accuracy and availability of the spectrum results. This paper introduces the basic ideas and calibration accuracy about the spectral calibration for the FIS and puts forward a new spectral calibration method based on calculating the precise value of the total optical path difference (TOPD). The TOPD of FIS is difficult to be precisely measured, but it is the core and key to the spectral calibration. In order to calculate the precise TOPD, this paper proposes the idea how to traverse the TOPD and analyzes the spectrum drift. During the calibration, all the possible values of the TOPD participate in the spectrum reconstruction flow to carry out spectrum recovery and analysis. Ultimately the TOPD with the minimum spectrum drift will be achieved, namely solution value of the TOPD. This method can accurately resolve the TOPD of the FIS and then calibrate the spectrum with high accuracy. In addition, the paper introduces the detailed and complete spectral calibration flow and obtains the center wavelength value of every band and wavenumber resolution. Moreover, the paper designs the main parameters of the typical FIS and generates its simulation interference data. Using the above method to calibrate the simulation data, the analysis and verification of the spectral calibration results proves that the calibration precision of wavenumber resolution achieves 0.000 25 cm⁻¹ or above.
傅里叶干涉光谱仪（FIS）获取光谱的干涉数据信息，在光谱数据处理过程中，会对干涉信息进行一系列光谱重建以获得最终的光谱信息数据。光谱校准是FIS光谱重建的关键步骤，它直接决定了光谱结果的准确性和可用性。本文介绍了FIS光谱校准的基本思想和校准精度，并提出了一种基于计算总光程差（TOPD）精确值的新光谱校准方法。FIS的TOPD难以精确测量，但它是光谱校准的核心和关键。为了计算精确的TOPD，本文提出了遍历TOPD的思路并分析了光谱漂移。在校准过程中，TOPD的所有可能值都参与光谱重建流程以进行光谱恢复和分析。最终将获得光谱漂移最小的TOPD，即TOPD的解值。该方法能够准确求解FIS的TOPD，进而高精度地校准光谱。此外，本文介绍了详细完整的光谱校准流程，并获得了每个波段的中心波长值和波数分辨率。而且，本文设计了典型FIS的主要参数并生成了其模拟干涉数据。使用上述方法对模拟数据进行校准，光谱校准结果的分析与验证表明波数分辨率的校准精度达到0.000 25 cm⁻¹及以上。
