Investigation on characteristic of LED power density via tapered fiber

In this paper, a tapered fiber for improving the power density of the Light Emitting Diode (LED) was designed. Numerical simulation showed that the tapered fiber makes the LED diverging light sources converge on the microscopic area, which makes the LED available for biomedical photonic imaging in the microenvironment. Based on the Monte Carlo Ray Tracing Method, we obtained the law of spot illumination and divergence angle when the light passes through the different parameters tapered fiber. In addition, the tapered fiber was designed as a spiral shape with steadily changing slope, and the effect of the spiral-bending coefficient on the light-gathering properties of the fiber was studied. The concentrating performance of tapered fiber is related to the length, size, and spiral-bending coefficient. The tapered fiber can effectively reduce the illuminant area and improve the power density of the light source.