Fig. 1. Schematic diagram of cryogenic mid-infrared trap detector

Fig. 2. Structure and principle of integrating sphere

Fig. 3. Schematic diagram of micro integrating sphere structure

Fig. 4. Photos of experimental samples

Fig. 5. SRI 1000 hand-held emissivity measuring instrument

Fig. 6. Schematic diagram of test for specific wavelength reflection characteristics

Fig. 7. Schematic diagram of diffuse reflection coordinate system

Fig. 8. Reflet 180S BRDF test system

Fig. 9. Variation curves of reflected radiation intensity with test angles

Fig. 10. Near infrared BRDF curves of different samples

Fig. 11. Photos of samples used for surface testing

Fig. 12. Photos of surface morphology

Fig. 13. Pseudo-color diagram of sample surface height

Fig. 14. Vertical profile curves of sample surface

Fig. 15. Scanning electron microscope image

Fig. 16. Diagram of produced integrating sphere

Fig. 17. Variation curve of light intensity attenuation ratio of integrating sphere with reflectivity of inner cavity wall

Fig. 18. Spectral response curves of detector chip before and after integrating sphere installation

Fig. 19. Schematic block diagram of infrared detector test system