Coupling Filter Based On Axis-shifted Twin-core Fiber

To solve the above problems, a coupling filter based on the axis-shifted twin-core fiber is proposed here. The filter fusion splices the cores of two single-mode optical fibers with the central core of a length L two cores of the same axis-offset dual-core optical fiber. Due to the waveguide symmetry of the central core of the single-mode fiber and the axis-shifted dual-core fiber, this filter facilitates the alignment of the splice points of the dual-core fiber and the single-mode fiber core for mode field matching, and the production time is shorter. It can reduce the insertion loss between the single-mode fiber and the dual-core fiber, thereby improving the performance of the entire filter.