Fig. 1. Schematic diagram of VIPA spectrometer. (a) Structure diagram; (b) schematic diagram of 2D spectral image

Fig. 2. Schematic diagram of broadband CO₂ absorption spectrum measurement device

Fig. 3. Flow of spectral inversion. (a) Pure N₂ spectral image; (b) pure CO₂ spectral image;(c) pure CO₂ absorption image; (d) schematic diagram of spectral calibration

Fig. 4. Schematic diagram of instrument lineshape function inversion. (a) Theoretical absorption of pure CO₂; (b) pure CO₂ theoretical and broadened theoretical transmission spectra; (c) measured absorption, theoretical absorption, and residual data of pure CO₂; (d) photograph of instrument lineshape function

Fig. 5. Photograph of CO₂ absorption spectrum. (a) Measured spectrum, line-by-line integrated simulated spectrum, and residual error from 6900 cm^-1 to 7000 cm^-1 of pure CO₂ at the pressure of 200 mbar and 298 K conditions; (b) partial fitting results for the 6943-6948 cm^-1 band; (c) partial fitting results for the 6970-6976 cm^-1 band