Integrated optical switches using deuterated liquids for increased bandwidth

An electro-wetting optical device comprising:

• a substrate supporting at least a first waveguide, a second waveguide, and a coupling region between the first and second waveguides;
• a first portion of a first optical liquid, the first optical liquid having a first refractive index, and a second portion of the second optical liquid, the second optical liquid having a second refractive index, at least one of the first optical liquid and the second optical liquid being deuterated;
• wherein the first portion of the first optical liquid and the second portion of the second optical liquid are moveable relative to the coupling region whereby, under a first switching configuration the first optical liquid is positioned at the coupling region so as to provide a first effective refractive index for light propagating along the first waveguide and under a second switching configuration the second optical liquid is positioned at the coupling region so as to provide a second effective refractive index for light propagating along the first waveguide.