Abstract: An integrated structure and method of its fabrication are presented. The integrated structure comprises at least one waveguide; at least one fluid chamber; and an electrode assembly. The fluid chamber is associated with said at least one waveguide and configured and operable to selectively allow one or more droplets of said fluid from the fluid chamber to access at least a portion of the waveguide thereby selectively creating one or more fluid-waveguide interfaces and affecting the effective refractive index of the waveguide and light coupling at said one or more interface. The electrode assembly is configured and operable to induce an electric field within said at least one fluid chamber to affect the fluid-waveguide interface, thereby affecting light propagation in said waveguide and accordingly affecting optical properties of the integrated structure.