The boundary line of the two parts of the filter is set on the side of the maximum position of the second-order diffraction of the 380nm spectral line near the short-wave spectral line, and it is not required to coincide exactly with the maximum position of the second-order diffraction, allowing sufficient processing and assembly margins. Secondly, the spatial position of the optical filter is reasonably matched with the spectral position of the grating imaging spectrometer. Spatial matching, the filter has different regions with different transmittance characteristics, see figure 1, the filter is divided into two areas, area 1 has a transmittance of 90% for 380-760nm light waves, cut-off filter area 2 has a transmittance of 380-450nm light waves not greater than 2%, and at the same time has a transmittance of 450-900nm The transmittance of the light wave is 90% the dividing line of these two areas does not need to coincide with the position of the first-order diffraction maximum of the 760nm light wave, and only needs to roughly estimate the position, that is, the vertical distance x= f 0 First, it is necessary to design a bandpass filter with a suitable wavelength range in a targeted manner for use with the grating imaging spectrometer spectrum. Using the grating imaging spectrometer spectral space matching method proposed by the present invention, the above grating imaging spectrometer is implemented to eliminate the non-measured sub-spectrum. The spectral space matching method is suitable for the technical field of the grating dispersion imaging spectroscopy in which an area-array detector is used as a receiving device. The processing cost and the assembling difficulty are reduced. The optical filter has high tolerance performance of the installation position and is convenient and rapid to use. The boundary of the optical filter can be basically coincident with the vertical center line of the detector. According to the invention, the transmission wavelength range of the cut-off optical filtering region on the optical filter is widened, so that mutually overlapping regions exist at both sides of the optical filter, the requirement for eliminating aliasing of a secondary spectrum is met, and in the installing process, the positions of overlapped spectral lines of the secondary spectrum only need to be roughly estimated, the optical filter does not need to be strictly and geometrically aligned with a spectrum on a detector of the grating imaging spectrometer and a high-precision alignment device is also not required to carry out accurate alignment of the position. A working wavelength of lambda 0 to lambda 1 of the imaging spectrometer to be matched is combined the partitional design is adopted to an optical filter the optical filter adopts the following regional division that one side of a boundary has a passband range of lambda 0 to lambda 1, the other side of the boundary is provided with a cut-off optical filtering region and the cut-off optical filtering region has a cut-off range of lambda 0 to half lambda 1 and has a passband range of half lambda 1 to lambda 1. The invention provides a spectral space matching method for a grating imaging spectrometer.
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