"Photobleached and e-Beam Bleached Waveguides When it is desirable to avoid wet chemicals, such as different solvents and developers, alternative approaches to waveguide patterning have to be used. One such approach is based on bleaching of the EO polymers. Decomposition of the chromophore molecules under direct UV or electron beam irradiation reduces the refractive index of chromophore containing polymers (Figure 4(a)) [12,13]. High energy photons or electrons break the bonds, chromophore molecules decompose and the material color bleaches out. Created refractive index contrast can be ~0.06–0.07—enough for efficient light guiding."