Tapered Plastic Optical Fiber, Optical Transmission Characteristics And Applied Research

The plastic optical fiber(POF) have many advantage in short distance communication, such as fine flexibility, easy-connecting , low cost and so on. In the field of sensing, compared with the silica optical fiber(SOF), the POFs have higher sensitivity and bigger measurement range. So the plastic optical fiber is being paid more and more attention and it has the quite considerable potential market and the application prospect.This paper studies on the theory of mode coupling and power flow equation of plastic optical fiber waveguide. Ray tracing method of plastic optical fiber is simply introduced and simulated. Based on the ray tracing method of geometric optics, the propagation property of rays in tapered plastic fiber is analyzed and simulated. The meridian ray and the skew ray propagation formula for tapered plastic fiber is derived. The result shows that it is appropriate to use a smaller taper angle when the tapered plastic optical fiber is used as collimation.The experiment of large-core plastic optical fiber thermal pre-elongated taper is introduced. Through experiment repeatedly, the paper proposed the good parameter of plastic optical fiber thermal pre-elongated taper, and gave some test and analysis on the thermal pre-elongated tapered plastic optical fiber. The far-field characteristics when LD goes through telescope system,multi-mode fiber system and tapered plastic optical fiber system are studied. The telescope system has good beam collimation, and the far-field beam appears ring shape for diffraction. Multi-mode fiber system has the characteristic of model dispersion which makes the complex spatial coherence less and the light beam uniformity increased. With both characteristics, tapered plastic optical fiber system makes the light have partial coherence and reduces the beam divergence angle, which makes the light quality the best.Information is carried by light beam from light sources in optical fiber communication. The most common light sources are semiconductor laser and light emitting diode. In the last chapter, the research on coupling between LED and optical fiber is given. It puts forward some methods to improve beam divergence angle of LED and the coupling efficiency between LED and optical fiber. The experiment shows that tapered plastic optical fiber has good efficiency in improving light coupling efficiency.