1. Luminaire distribution --- Optical lens
Non-imaging secondary optics design: more effective for illumination distribution with isoluminance energy.
2. Luminaire distribution efficiency --- light-extraction efficiency of lens
Figure 1:15%-20% total light flux is confined within 60—90 degree circumferential angle.
Figure 2: Light outside of 60-90 degree angle is unwanted light.
Figure3: Light in larger luminous angle is more efficient for illumination on the ground.
3. Luminaire distribution efficiency --- System optical loss
Integrated Array lens module design with advantages of water proof, dust proof, and no optical loss; No optical surface-loss and dielectric-loss, no optical loss of Fresnel effect; Optical loss maybe more than 15% if maximum luminous intensity angle was larger than 67 degree, and optical loss is around 10% for design with luminaire cover.