Amplified oscillation in a slab-type optical directional coupler with an activated rhodamine 6G top layer

Abstract
Guide‐length‐dependent amplified oscillation of coupled waves in a slab‐type optical directional coupler covered with a triangular rhodamine 6G activated top layer was observed. This is an application of a thin‐film optical‐waveguide evanescent dye laser. Analysis using the complex coupling theory was compared with experiments.