Liquid-core/liquid-cladding integrated silicon ARROW waveguides

The fabrication and characterization of a liquid-core/liquid-cladding integrated antiresonant reflecting optical waveguide (L2-ARROW) is presented. In this waveguide, the light is confined vertically by the ARROW mechanism, whereas the lateral confinement is obtained by using liquid-core/liquid-cladding (L2 waveguides) with different refractive indexes. This approach permits to realize L2 waveguides with very low refractive index core (n ≈ 1.333) and represents a new solution to solve the difficulty to reduce the optical losses in 2D-ARROWs due to the TM polarization in lateral direction. The device has been fabricated with standard silicon technology. The results show that the optical properties can be tuned by changing the type and the flow velocity of the core and the cladding liquids.