Experimental research on plastic optical fiber power coupler

Abstract

We performed some experimental studies on a new type cost-effective power coupling method for large-core POFs, and proposed a novel 1×4 plastic optical fiber (POF) power coupler which is different from fused-taper type and mixing rod POF couplers. Loss factors of this coupler are also analyzed theoretically. This coupler is based on thermal feature of POF, the two end of coupler is composed of fused-drawn tapered fiber and thermal-contracted tapered fiber, respectively, which is characterized as simple configuration and easily fabrication. The performance parameters of this coupler including excess loss, insertion loss, and channel cross-talk were measured. The loss and cross-talk can meet the practical requirement, and the channel uniformity is not desirable. The main issue is technical process. In our experiments, heated-drawing and contracting is controlled manually, the uniformity is deteriorated greatly, moreover, the distortion of POF during drawing and contracting is inevitable, as a result it leads to large bending loss. In addition, the termination of the taper and the alignment of optical path influences seriously on performances. Compared with mixing rod coupler, the coupler has advantages of simple structure, easy fabrication due to the absence of the mixing rod middle component. The further research on this coupler is to draw and contract fiber mechanically rather than manually, to enhance the uniformity, and to reduce loss further.