Waveguides in three-dimensional photonic bandgap materials for particle-accelerator on a chip architectures

A promising concept for making high-energy particle accelerators less expensive and more compact is to make use of axially polarized optical modes supported by line defect waveguides in three-dimensional photonic bandgap materials. Following a theoretical proposal by B. M. Cowan we here present the first experimental realization of corresponding pilot samples for three-dimensional photonic bandgap particle-accelerator segments. The samples have been fabricated using a combination of direct laser writing and an improved silicon-double-inversion procedure. Regarding optical characterization we have performed transmittance measurements providing unambiguous evidence of a waveguide mode with axial polarization. These results represent an important first step towards actually putting into practice future “particle-accelerator on a chip” architectures.