Acceptance-angle measurement of multimode fibers: a comparison of techniques

A number of techniques for measuring multimode fiber acceptance angle are described, and the general requirements and problems particular to each technique are discussed. An experimental comparison is presented of a fiber acceptance-angle technique and a fiber radiation-angle technique. Results are presented on quasi-step index and also plastic-clad silica fibers. It is concluded that the radiation-angle technique offers simplicity of operation with unambiguous results and may, therefore, be a suitable standard method for testing optical fibers.