Protection layers for polymer modulators/waveguides

A polymer waveguide/modulator comprising:

• a lower cladding layer having a refractive index;
• a polymer core having a refractive index;
• an upper cladding layer having a refractive index;
• a first protection or barrier layer sandwiched between the lower cladding layer and the core, the first protection or barrier layer being designed to protect the lower cladding layer and the core from solvents and gases and to prevent current leakage between the lower cladding layer and the core, and the first protection or barrier layer being optically transparent and designed with a refractive index less than, greater than, or the same as the refractive index of the core or substantially equal to the refractive index of the lower cladding layer;
• a second protection or barrier layer sandwiched between the core and the upper cladding layer, the second protection or barrier layer being designed to protect the upper cladding layer and the core from solvents and gases and to prevent current leakage between the upper cladding layer and the core, and the second protection or barrier layer being optically transparent and designed with a refractive index less than, greater than, or the same as the refractive index of the core or substantially equal to the refractive index of the upper cladding layer;
• and
• wherein the polymer core includes ultem polymer material with a refractive index of 1.7 and the first and second protection or barrier layers each include two sub-layers, with a sub-layer adjacent the core having a 1.69 refractive index and a sub-layer adjacent the lower cladding layer and the upper cladding layer, respectively, having a 1.68 refractive index.