Mismatched directional couplers.
Various twin-core couplers composed of mismatched optical fibers are capable of complete power transfer over lengths only moderately longer than their matched analogs. Examples include tapered and piecewise-continuous mismatched couplers. These linear couplers also provide insight into the mechanism of nonlinear coupling because nonlinearity induces periodic mismatching betweén twin cores that are axially uniform.
Snyder
A W
AW
Chen
Y
Y
Rowland
D
D
Mitchell
D J
DJ