Research On Coaxial Optical Fiber Based Splitter And Its Application

Coaxial dual-waveguide structured optical fiber contains central core and a annular corein a fiber cladding, which can serve as the optical transmission medium and also can be usedto produce the fiber optic device to achieve the functions of exchange of the optical powerand selection of the wavelength. When coaxial dual-waveguide structured optical fiber isinfluenced by factors such as stress, temperature and twist etc, its internal transmissioncharacteristics of the light will change so many experts and scholars using thesecharacteristics to produce wavelength division multiplexer and filter. because of the coaxialdual-waveguide structured optical fiber has compact structure, high integration, and the twocores has a good consistency to the disturbance of the external environment, so it is widelyused in the field of optical fiber communication and optical fiber sensing.In this paper, we proposed a novel integrated fiber coupler based on the coaxialdual-waveguide structured optical fiber. We made a detailed theoretical analysis on thetransmission and coupling characteristics of coaxial dual-waveguide structured optical fiberbased on the multilayer uniform circular waveguide theory. Optical simulation method basedon Beam prop was used to simulate and analyze the coaxial dual-waveguide structured opticalfiber beam splitter’s characteristics, such as taper length, taper waist diameter, the thicknessand the position of the annular core of coaxial dual-waveguide fiber, and the difference ofreflex index between central core and annular core of coaxial dual-waveguide fiber. Thesimulation results confirmed the correctness of the design. Using the coaxial dual-waveguidestructured optical fiber made by our own laboratory, we fabricated fiber beam splitter with thefused and tapering technology. We made a coaxial dual-waveguide fiber beam splitter andachieved spectral function of optical signal under the specific operating wavelength of980nmand1480nm.