Advances in thin film photonics: Materials, science and technology

Control of refractive index in amorphous silicon materials is investigated. Elementary waveguide structures were prepared on two micron thick amorphous silicon by photo lithographic patterning of a silver masking layer. Hydrogen was implanted at fluence of ∼ 5 × 10¹⁷ cm² for three energies, 50, 100 and 175 KeV yielding a total does of ∼ 1.5 × 10¹⁷ cm² consistent with a 10% increase in atoms due to the hydrogen addition. The optical properties of the implanted and non-implanted regions were probed as a function of low temperature annealing. The optical band gap shift to higher energy was consistent with hydrogen addition. Some darkening, absorption increases, were noted on the implanted regions. However, low temperature annealing is known to remove dangling bond damage in amorphous silicon. Prospects of utilizing these waveguides to probe light induced optical changes in amorphous silicon is described as well as the prospects of more advanced devices.