Output coupling efficiency of a One-Dimensional array of light emitters.

A one-dimensional array of rectangular light emitters is described. The light is generated isotropically inside the elements under the e-beam impact on the top surface of the elements. In the general case, asymmetric guides with a different cladding on the two sets of parallel sides are considered. The fraction of the generated light that can propagate along a given dielectric guide is calculated in the framework of geometrical optics, as a function of the core-cladding refractive indexes. The coupling of the guided light flux from a symmetric (N(o) = 1.84; N(x) = N(y) = 1.46) and an asymmetric (N(o) = 1.88; N(x) = 1.84, N(y) = 1.46) waveguide to an f-number 1 collecting system using hemispherical and cylindrical couplers is calculated. It is shown that coupling efficiencies as high as 25% and 9% could be achieved with the symmetric and the asymmetric guides, respectively, attaching a larger size hemisphere to the flat output face of the guide. For asymmetric guides the coupling efficiency achievable with cylindrical and hemispherical couplers are comparable. However, for a symmetric guide a cylindrical coupler is considerably-efficient than a hemisphere.