Fig. 1. Optical properties of sphere

Fig. 2. Related structures of light recycling channel. (a) Structure of light recycling channel; (b) light recycling channel etendue conservation

Fig. 3. Basic optical path with light recycling channels

Fig. 4. Modeling of light recycling lens. (a) Main view; (b) top view

Fig. 5. Modeling of light recycling module and optical path. (a) Modeling of light recycling module; (b) optical path diagram

Fig. 6. Effect of four variables on far-field power-density enhancement. (a) Light recycling lens exit aperture diameter l₁; (b) reflectivity of high reflective film r₁; (c) LED surface scattering rate r₂; (d) LED area s₁

Fig. 7. Light recycling module and experiments with 365 nm spot example. (a) Experiment of light recycling module; (b) model of light recycling module; (c) example of 365 nm spot

Fig. 8. Comparison between simulation and experiment far-field power-density enhancement for three wavelengths. (a) 365 nm; (b) 385 nm; (c) 455 nm