Focusing properties of mushroom microlenses

Focusing properties of a novel type photoresist microlens are studied. A specific character of the microlens is its mushroom shape. Recently it was predicted and experimentally revealed that such a lens integrated with a light-emitting diode is capable of enhancing its output efficiency and directivity. In our paper we describe the true electromagnetic performance of a mushroom lens by applying a mathematically rigorous method of boundary integral equations. Numerical results are presented for the mushroom lens illuminated with a plane E-polarized wave and include figures describing the evolution of the lens focal spot and near field maps.