Radiation from Side‐Emitting Optical Fibers and Fiber Fabrics: Radiometric Model and Experimental Validation

Abstract

Side‐emitting optical fibers are diffuse light sources that emit guided light through their cladding. Herein, two models to predict the generated radiation field are derived: one for the case of a cylinder source and one for a line source. The approach is based on the radiometric approximation and considers longitudinal and angle‐dependent emission. Experimental validation is provided for the model parameters and the radiation field. It is shown that the longitudinal characteristic is relevant in proximity to the emitter's surface and that the angular dependency determines the far field of emission. Comparison to the experiment shows that the cylinder source model allows for only slightly more accurate prediction at the cost of significantly higher computational effort. A combination of model and measurements is then used to predict the illumination performance of side‐emitting fibers and fiber fabrics.