The Study of 2X2 Fiber Coupler with Tunable Couple Ratio

摘要

Making the middle arm of parallel arranged 3X3 fiber coupler feedback, we can gain a kind of fiber coupler which couple ratio can be controlled. If a parallel arranged 3X3 fiber coupler is not completely parallel, as long as the coupling coefficient k_1 between two adjacent fibers is greater than two time of the coupling coefficient k_2 between two not adjacent fibers F_1 and F_3, couple ratio can be controlled efficiently.