Fig. 1. Schematic of laser beam passing through diffractive micro-lens array

Fig. 2. Working principle of measuring system and coordinate system conversion. (a) Working principle of measuring system; (b) coordinate system conversion

Fig. 3. Influence of spot size on detecting angle

Fig. 4. Experimental measurement results of BRDF for polytetrafluoroethylene plate. (a) Initial measurement result; (b) interpolated result

Fig. 5. Gray scale as a function of illuminance after mapping

Fig. 6. Spot illuminance distributions in focal plane when focal length of lens is 300 mm. (a) Three-dimensional distribution; (b) one-dimensional distribution

Fig. 7. Spot illuminance distributions in focal plane when focal length of lens is 500 mm. (a) Three-dimensional distribution; (b) one-dimensional distribution

Fig. 8. Spot illuminance distributions in different defocus distances when focal length of lens is 300 mm. (a) Defocus distance of 5 mm; (b) defocus distance of -5 mm

Fig. 9. Spot illuminance distributions in different defocus distances when focal length of lens is 500 mm. (a) Defocus distance of 5 mm; (b) defocus distance of -5 mm

Fig. 10. Variation coefficient of spot illuminance in target plane as a function of defocus distance for two cases. (a) Focal length of lens is 300 mm; (b) focal length of lens is 500 mm