Birefringence control for ion-exchanged channel glass waveguides

We show that at 1.55-μm wavelength the waveguide birefringence of ion-exchanged channel waveguides in glass can be broadly tuned by a potassium and silver double-ion exchange. Two different potassium and silver double-ion-exchange processes are used to make surface waveguides with negligible waveguide birefringence. This process is crucially important in the manufacture of devices for dense wavelengthdivision multiplexing systems. The dependence of the waveguide birefringence on the channel width is also reported.