Wide single-mode channels and directional coupler by two-step ion-exchange in glass

A simple model for the characterization of single-mode channel waveguides fabricated by a two-step K/sup +/-Na/sup +/ ion exchange in glass is described. The model can be extended to other types of exchange or substrates. A directional coupler has been designed, fabricated, and measured to show both the usefulness and accuracy of the model and also the relaxation of the fabrication tolerances provided by the two-step ion exchange.<
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