Design and Optimization of Dot Pattern in Illumination Lightpipe of Natural Light Guiding System

摘要

In recent years, the practicality and importance of the illumination with sunlight are getting more seriously concern in public. The reason is that natural light is non-polluting, energy-saving, and healthy in comparison with traditional light sources. Therefore, our research focuses on how to replace the artificial sources by natural light. A Natural Light Guiding System has collecting, transmitting, and lighting parts. For replacing the traditional sources, the lighting part should have similar characteristic, such as intensity distribution and geometric parameters, to artificial sources. In this paper, we design, simulate, and optimize illumination lightpipe with dot pattern to redistribute the collecting sunlight from Natural Light Guiding System. The lightpipe includes input, system, and output parts. In the input part, we design a coupler to improve the coupling efficiency with natural light. For optimizing the efficiency of the coupler, we evaluate the relationship between the distance that is from the fiber to the lightpipe and the coupled power. In the system part, the sunlight is locked by total internal reflection, TIR, so we design dot pattern to scatter the locked sunlight for uniform lighting. In the output part, a uniform illumination is our goal. For designing the percentage of the surface will be covered by dot pattern, we offer a design theory and simulate the efficiency.