| 摘要 |
A technique for the preparation of waveguides from optic material, comprises creating the total reflection by reducing the refraction index in the regions surrounding those areas which become light conducting by applying a high electric field over a certain period of time, which leads to ions being transported away through the material without them being replaced by fresh ions. Preferably the optic material is an alkali-rich glass such as soda-lime or boron silicate glass, or it is a semiconductor-doped glass, or it is based on alumina. The following waveguide preparation methods based on the use of conventional (field-assisted) ion exchange techniques to define a core and mantle, are also claimed : (i) polarisation of the substrate after the core and mantle have been defined, so that the refraction index is reduced to a value equal to or greater than that for the core by polarising the mantle ; and (ii) polarisation of the core periodically in the length direction and polarisation of the mantle continuously in the length direction, once the core and mantle have been defined, so that the average refraction index value for the core is reduced to a value less than the refraction index for the mantle. |
