LED illuminating system using photonic crystal fiber light pipe
Author(s): Shen Chang-yu, Jin Shang-zhong
Affiliation(s): Optical Engineering, China JiLiang University
Topic: 5. Optoelectronic Sensor-Technologies and Light Sources
In order to realize the LED’s uniform illuminating in general illuminating, a LED uniform illuminating light pipe system was designed. The high brightness LEDs were assembled at the light pipe’s terminal symmetry using as the light source. The naked large diameter photonic crystals fiber was used as the light pipe. The photonic crystal fiber’s diameter was ranged from 8mm to 150mm, and the center air hole diameter was ranged from 7mm to 149mm accordingly. The illuminating system’s working principle is using the light leaking from the photonic crystals fiber as the illuminating light. When the light emitted from the high brightness LEDs is coupled into the photonic crystals fiber light pipe, the leakage loss of the photonic crystals fiber depends on the number of rings of the air hole around the center air hole. In our system, keeping 3 to 4 rings of the air hole in the photonic crystals fiber, 99% of light emitted from the LED was leaked out as the illuminating light after propagating 1m in the fiber. The LEDs were assembled at the fiber’s terminal symmetry, and the light emitted from the LEDs was coupled into the fiber symmetry, the 97% uniform illuminating light was obtained.