Nanoporous liquid core waveguides are fabricated by selectively UV modifying a nanoporous polymer. The
starting point is a diblock polymer where 1,2-polybutadiene (PB) molecules are bound to PDMS. When the PB
is cross linked it self-assembles into PB with a network of 14 nm diameter PDMS filled pores. When the PDMS
is etched, the hydrophobic PB is left with a porosity of 44%. The polymer is subsequently UV exposed through
a shadow mask. This renders the exposed part hydrophilic, making it possible for water to infiltrate these areas.
Water infiltration raises the refractive index, thus forming a liquid core waveguide. Here we present both the
fabrication scheme and characterization results for the waveguides.