Numerical analysis of efficient light extraction with an elliptical solid immersion lens.

We introduce and analyze a design concept based on nonspherical solid immersion lens (SIL) geometry. We find via finite difference time domain (FDTD) simulations that elliptical solid immersion lenses (eSILs) exhibit a notably improved emission directionality compared to the standard SIL design. Large light-collection efficiencies are achieved even for small numerical apertures (NAs). For example, using a NA as low as 0.3, over 65% of the total light emitted by a dipole can be collected.