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Faculty of Electrical Engineering and In­for­ma­ti­on Technology

Investigation of deuterated planar optical waveguide materials


In order to increase the performance of photonic integrated filter structures, low loss waveguides are required. At the Chair of High Frequency Technology, these waveguides are manufactured using plasma-enhanced chemical vapor deposition (PECVD). In this case, hydrogen-containing gases are usually used, which lead to undesired hydrogen compounds, such as Si—H compounds, in the waveguide layer. The harmonics of these molecules absorb part of the C-band (1530-1565nm) optical signal power, resulting in an increase in waveguide attenuation.

Various materials with different refractive indices are being investigated to reduce waveguide attenuation. These include, in particular, silicon-based waveguide materials such as silicon oxycarbide and silicon oxynitride. By adding deuterium in the waveguide manufacturing process, the critical absorption areas in the spectrum are to be shifted and the material attenuation reduced. This is intended to provide insights into the optical properties of deuterated waveguide materials.

  • Recording the absorption spectrum of different waveguide materials
  • Investigation of the influence of the interpretation of the materials
  • Optimization of the damping value through different parameter variations