Modeling and near-field measurements of strip-loaded Er-doped sol-gel waveguides

For integrated optical amplifiers to be efficient, losses must be minimized. An important source of losses comes from the coupling, and it is due to the modal mismatch between the amplifying channel waveguide and the connected fibers. In order to assess the coupling losses of our Er+- doped-glass strip-loaded waveguides, we observed the mode shapes by near-field imaging and compared them with the results of numerical simulations performed by using a 3D Beam Propagation Method. Important information about the critical parameters of the fabrication process have been obtained.