Abstract: A fluorescent low pressure discharge lamp is provided with axially mounted cold-cathode electrodes consisting of a sintered shaped mixture of inorganic material including about 50-90% by weight of tungsten and the remainder BaO or a mixture of BaO, CaO and SrO and oxides of Y, Zr or Hf or the rare earths. The electrodes have a uniform density throughout with a porosity of less than 10%.

Abstract: An actively phase matched waveguide structure suitable for use as a frequency doubling device is described. The device includes a non-linear optical waveguide and phase matching of the waveguide is controlled by an electrically operated light modulator which is spaced apart from the waveguide. The modulator includes one or more electrodes disposed on a substrate and an elastomeric transparent gel which has a metallic coating on its upper surface. Application of a voltage between the metallic upper surface and the electrodes causes a deformation in the gel which alters the gap between the upper surface of gel and thus provides phase matching.