Dual-core fiber as a tunable directional coupler.
The bending-induced birefringence in a fiber loop is used to restore locally perfect coupling conditions between the two slightly detuned cores of a dual-core fiber. It is also shown that varying the angle between the birefringence and the core's axis allows one to obtain perfect control (0-100%) of the coupling ratio.
D
D
Drolet
R
R
Vallée