Spectral calibration for convex grating imaging spectrometer

Jiankang Zhou; Xinhua Chen; Yiqun Ji; Yuheng Chen; Weimin Shen

doi:10.1117/12.2038150

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19 December 2013 Spectral calibration for convex grating imaging spectrometer

Jiankang Zhou, Xinhua Chen, Yiqun Ji, Yuheng Chen, Weimin Shen

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Proceedings Volume 9045, 2013 International Conference on Optical Instruments and Technology: Optoelectronic Imaging and Processing Technology; 90451U (2013) https://doi.org/10.1117/12.2038150
Event: International Conference on Optical Instruments and Technology (OIT2013), 2013, Beijing, China

Abstract

Spectral calibration of imaging spectrometer plays an important role for acquiring target accurate spectrum. There are two spectral calibration types in essence, the wavelength scanning and characteristic line sampling. Only the calibrated pixel is used for the wavelength scanning methods and he spectral response function (SRF) is constructed by the calibrated pixel itself. The different wavelength can be generated by the monochromator. The SRF is constructed by adjacent pixels of the calibrated one for the characteristic line sampling methods. And the pixels are illuminated by the narrow spectrum line and the center wavelength of the spectral line is exactly known. The calibration result comes from scanning method is precise, but it takes much time and data to deal with. The wavelength scanning method cannot be used in field or space environment. The characteristic line sampling method is simple, but the calibration precision is not easy to confirm. The standard spectroscopic lamp is used to calibrate our manufactured convex grating imaging spectrometer which has Offner concentric structure and can supply high resolution and uniform spectral signal. Gaussian fitting algorithm is used to determine the center position and the Full-Width-Half-Maximum（FWHM）of the characteristic spectrum line. The central wavelengths and FWHMs of spectral pixels are calibrated by cubic polynomial fitting. By setting a fitting error thresh hold and abandoning the maximum deviation point, an optimization calculation is achieved. The integrated calibration experiment equipment for spectral calibration is developed to enhance calibration efficiency. The spectral calibration result comes from spectral lamp method are verified by monochromator wavelength scanning calibration technique. The result shows that spectral calibration uncertainty of FWHM and center wavelength are both less than 0.08nm, or 5.2% of spectral FWHM.

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Jiankang Zhou, Xinhua Chen, Yiqun Ji, Yuheng Chen, and Weimin Shen "Spectral calibration for convex grating imaging spectrometer", Proc. SPIE 9045, 2013 International Conference on Optical Instruments and Technology: Optoelectronic Imaging and Processing Technology, 90451U (19 December 2013); https://doi.org/10.1117/12.2038150

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