Abstract: An optical channel switching element routes optical signals between optical waveguides or optical fibers by creating a transmit or reflect state in a polymer waveguide crossing junction by utilizing Total Internal Reflection (TIR) off a trench placed between the waveguide paths. The presence of a fluid or gel (usually selected to match the waveguide refractive index) within the trench creates a transmit state (no light is reflected) allowing light to continue along the initial waveguide path. The lack of index matching fluid at the waveguide junction, or presence of an air bubble, creates a TIR state (all light is reflected and none is transmitted) causing the light to reflect off of the trench and continue along the path of the crossing guide.