Low-loss semiconductor hollow waveguide with GaAs/AlAs multilayer mirrors for widely tunable waveguide devices

In this paper, we present the design of low-loss and polarization-insensitive semiconductor hollow waveguides using a highly reflective GaAs/AlAs mirrors. We experimentally demonstrate a low-loss slab hollow waveguide with a variable air core, exhibiting a low propagation loss of below 0.2 dB/cm.