Fig. 1. Diagram of radiation calibration light path without infrared filter

Fig. 2. Diagram of radiation calibration light path with infrared filter

Fig. 3. Schematic of self radiation determination principle for infrared filter in cutoff band

Fig. 4. Radiation model from limited surface source to micro surface source

Fig. 5. Normalized spectral radiation responsivity of medium wave infrared detector

Fig. 6. Radiation calibration results without infrared filter (integration time is 0.8 ms). (a) Radiation responsivity; (b) gray value bias

Fig. 7. Radiation calibration results with infrared filter (integration time is 0.8 ms). (a) Radiation responsivity; (b) gray value bias

Fig. 8. Difference of radiation calibration results (integration time is 0.8 ms). (a) Relative difference of radiation responsivity; (b) absolute difference of gray value bias

Fig. 9. Radiation calibration results without infrared filter (integration time is 4.0 ms). (a) Radiation responsivity; (b) gray value bias

Fig. 10. Radiation calibration results with infrared filter (integration time is 4.0 ms). (a) Radiation responsivity; (b) gray value bias

Fig. 11. Difference of radiation calibration results (integration time is 4.0 ms). (a) Relative difference of radiation responsivity; (b) absolute difference of gray value bias

Fig. 12. Diagram of reflection imaging light path (angle between infrared filter and optical axis is 45°)

Fig. 13. Reflection imaging effect (angle between infrared filter and optical axis is 45°)

Fig. 14. Diagram of reflection imaging light path (filter is perpendicular to optical axis)

Fig. 15. Reflection imaging effect (filter is perpendicular to optical axis). (a) Lens surface; (b) Dewar window