Estimation of coupling power parameter of fused coupled fibers

摘要

Fiber couplers are widely used in telecommunication and industry as a passive splitting power device. The effectivepower coupling and transmitting from one fiber to another is mainly determined by both coupling length and couplingcoefficient. Coupling length can be calculated directly but for coupling coefficient it depends upon the refractive indexand separation fiber axis. After fusion processes of two SMF-28e~?couplers, the refractive index is unknown due tochange in the radius of fiber (r_(cladd)<40μm and r_(core)<1.5μm). Coupling coefficient range is obtained from a distribution ofcoupling ratio and compared with the empirical formula which also enables to calculate refractive index. In thisexperiment, coupling coefficient in the range of 0.6-0.9/mm is calculated as a function of separation fiber axis andrefractive index of core and cladding. The result shows a good correlation between experimental results and theoreticalcalculation.