Theoretical Analysis and Experimental Research on Coupling Characteristics of Symmetric Single-mode Twin-Core Fiber

摘要

According to the coupled-mode theory, the change rules of symmetric single-mode twin-core fibers' (TCFs') coupling coefficients versus their structural parameters are discussed. And the optical power in two cores is also analyzed by the coupled-mode theory. It shows that when the structural parameters and the input signal wavelength are fixed, the optical power in two cores is just related to TCF length and has a periodic variation phenomenon. To verify the correctness of the theoretical analysis, some corresponding experiments have been done, and the experimental results match the theoretical analysis very well, which is in error by less than 1 percent. It indicates this kind of symmetric TCF as a single-mode fiber coupler has a good application prospect.