Fig. 1. Normalized spectral curve

Fig. 2. Schematic diagram of the protection system

Fig. 3. Distribution of grayscale values. (a) Laser spot; (b) Background light

Fig. 4. Distribution of laser spot grayscale values after removing background light

Fig. 5. Curve of interference area with incident laser energy density under different F-numbers

Fig. 6. Transmittance vs wavelength curve of notch filter

Fig. 7. Desktop experimental system

Fig. 8. Condition of camera under 20 mW laser irradiation. (a) Imaging effect; (b) Grayscale value distribution

Fig. 9. Condition of camera under 40 mW laser irradiation. (a) Imaging effect; (b) Grayscale value distribution

Fig. 10. Effect of active protection measures. (a) Shutter opening; (b) Shutter closing

Fig. 11. Condition of the camera under 20 mW laser irradiation with notch filter. (a) Imaging effect; (b) Grayscale value distribution

Fig. 12. Condition of the camera under 50 mW laser irradiation with notch filter. (a) Imaging effect; (b) Grayscale value distribution